I can offer two texts in English for downloading.

At the first place there is this book of around 220 pages,
a collection of several basic topics in universal algebra:

UNIVERSAL ALGEBRA first edition (April 2008)

Then a shorter text, around 40 pages, on geometry. It assumes knowledge of basics
of lattice theory and contains full proofs of the coordinatization theorem
for projective planes and also the Bruck-Ryser theorem, without reference to
other results:

GEOMETRIES first edition (April 2008)

There are also three JPEG collections of books in Czech:

Univerzalni algebra a teorie modelu. SNTL, Praha 1976, 226 pp.J. Jezek, T. Kepka and P. Nemec: Distributive groupoids. Rozpravy CSAV, Rada mat. a prir. ved 91/3, 1981, 94 pp.

J. Jezek and T. Kepka: Medial groupoids. Rozpravy CSAV, Rada mat. a prir. ved 93/2, 1983, 93 pp.

In the past decades I was gathering a bibliography database of universal algebra
and several more or less related topics. It is now quite extensive and could be
considered almost complete for older universal algebra papers.
Perhaps it could be of some use for other people.
I can offer both the pdf and the source AMS-LaTeX files:

BIBLIOGRAPHY.pdf first release (April 2008)

BIBLIOGRAPHY.tex

R. Freese, J. Jezek, and J. B. Nation: Free lattices
Mathematical Surveys and Monographs 42. American Mathematical
Society, Providence, Rhode Island 1995.

J. Nečas a kolektiv: Aplikovaná matematika I, II (Applied
mathematics I, II), SNTL, Praha 1978, 2382 pp.

2. Groupoid

3. Lattice

4. FreeLat

2. Reduced dimension of primitive classes of universal algebras. Commentatationes Math. Univ. Carolinae 9, 1968, 103-108.

3. Primitive classes of algebras with unary and nullary operations. Colloquium Math. 20, 1969, 159-179.

4. Principal dual ideals in lattices of primitive classes. Commentatationes Math. Univ. Carolinae 9, 1968, 533-545.

5. On categories of structures and classes of algebras. Dissertationes Math. 75, Warszawa 1970.

6. An embedding of groupoids and monomorphisms into simpLe groupoids. Commentatationes Math. Univ. Carolinae 11, 1970, 91-98.

7. On atoms in lattices of primitive classes. Commentatationes Math. Univ. Carolinae 11, 1970, 515-532.

8. The existence of upper semicomplements in lattices of primitive classes. Commentatationes Math. Univ. Carolinae 12, 1971, 519-532.

9. Upper semicomplements and a definable element in the lattice of groupoid varieties. Commentatationes Math. Univ. Carolinae 12, 1971, 565-586.

10. J. Jezek and L. Beran: On embedding of lattices in simple lattices. Acta Universitatis Carolinae 13, 1972, 87-89.

12. Realization of small concrete categories by algebras and injective homomorphisms. Colloquium Math. 29, 1974, 61-69.

13. Algebraicity of endomorphisms of some relational structures. Acta Universitatis Carolinae 13, 1972, 43-52.

15. J. Jezek and V. Slavik: Some examples of primitive lattices. Acta Universitatis Carolinae 14, 1974, 3-8.

16. J. Jezek and T. Kepka: Extensive varieties. Acta Universitatis Carolinae 16, 1975, 79-87.

17. J. Jezek and T. Kepka: Free commutative idempotent abelian groupoids and quasigroups. Acta Universitatis Carolinae 17, 1976, 13-19.

18. J. Jezek and T. Kepka: The lattice of varieties of commutative abelian distributive groupoids. Algebra Universalis 5, 1975, 225-237.

19. J. Jezek and T. Kepka: Semigroup representations of commutative idempotent abelian groupoids. Commentatationes Math. Univ. Carolinae 16, 1975, 487-500.

20. J. Jezek and T. Kepka: Quasigroups, isotopic to a group. Commentatationes Math. Univ. Carolinae 16, 1975, 59-76.

21. Normal subsets of quasigroups. Commentatationes Math. Univ. Carolinae 16, 1975, 77-85.

22. J. Jezek, T. Kepka and P. Nemec: The category of totally symmetric quasigroups is binding. Acta Universitatis Carolinae 19, 1978, 63-64.

23. J. Jezek and T. Kepka: Atoms in the lattice of varieties of distributive groupoids. Colloquia Math. Soc. J. Bolyai 14. Lattice Theory, Szeged 1974. 185-194.

24. Intervals in the lattice of varieties. Algebra Universalis 6, 1976, 147-158.

25. Varieties of algebras with equationally definable zeros.Czechoslovak Math. J. 27, 1977, 394-414.

26. J. Jezek and T. Kepka: Varieties of abelian quasigroups. Czechoslovak Math. J. 27, 1977, 473-503.

27. Endomorphism semigroups and subgroupoid lattices. Colloquia Math. Soc. J. Bolyai 17. Contributions to Universal Algebra, Szeged 1975. 209-212.

28. EDZ-varieties: The Schreier property and epimorphisms onto. Commentatationes Math. Univ. Carolinae 17, 1976, 281-290.

29. J. Jezek and T. Kepka: Quasitrivial and nearly quasitrivial distributive groupoids and semigroups. Acta Universitatis Carolinae 19, 1978, 25-44.

30. J. Jezek and T. Kepka: Varieties of quasigroups determined by short strictly balanced identities. Czechoslovak Math. J. 29, 1979, 84-96.

31. A note on complex groupoids. Colloquia Math. Soc. J. Bolyai 29. Universal Algebra, Esztergom 1977. 419-420.

32. J. Jezek and V. Slavik: Primitive lattices. Czechoslovak Math. J. 29, 1979, 595-634.

33. Terms and semiterms. Commentatationes Math. Univ. Carolinae 20, 1979, 447-460.

34. The lattice of equational theories. Part I: Modular elements. Czechoslovak Math. J. 31, 1981, 127-152.

35. J. Jezek and T. Kepka: Torsion groupoids. Czechoslovak Math. J. 33, 1983, 7-26.

36. The lattice of equational theories. Part II: The lattice of full sets of terms. Czechoslovak Math. J. 31, 1981, 573-603.

37. J. Jezek and T. Kepka: Equational theories of medial groupoids. Algebra Universalis 17, 1983, 174-190.

38. J. Jezek and T. Kepka: Free entropic groupoids. Commentatationes Math. Univ. Carolinae 22, 1981, 223-233.

39. The lattice of equational theories. Part III: Definability and automorphisms. Czechoslovak Math. J. 32, 1982, 129-164.

40. Simple semilattices with two commuting automorphisms. Algebra Universalis 15, 1982, 162-175.

41. J. Jezek and T. Kepka: Simple semimodules over commutative semirings. Acta Sci. Math. 46, 1983, 17-27.

42. J. Jezek and T. Kepka: Semigroup representations of medial groupoids. Commentatationes Math. Univ. Carolinae 22, 1981, 513-524.

43. Free groupoids in varieties determined by a short equation. Acta Universitatis Carolinae 23, 1982, 3-24.

44. J. Jezek and J. Nesetril: Ramsey varieties. Europ. J. Combinatorics 4, 1983, 143-147.

45. The number of minimal varieties of idempotent groupoids. Commentatationes Math. Univ. Carolinae 23, 1982, 199-205.

46. J. Jezek and T. Kepka: Idealfree CIM-groupoids and open convex sets. Proceedings, Puebla 1982, Universal algebra and lattice theory. Lecture Notes in Math. 1004. Springer-Verlag. 166-175.

47. On join-indecomposable equational theories. Proceedings, Puebla 1982, Universal algebra and lattice theory. Lecture Notes in Math. 1004. Springer-Verlag. 159-165.

48. A note on isomorphic varieties. Commentatationes Math. Univ. Carolinae 23, 1982, 579-588.

49. J. Jezek and T. Kepka: Permutable groupoids. Czechoslovak Math. J. 34, 1984, 396-410.

50. J. Jezek and T. Kepka: Distributive groupoids and symmetry-by-mediality. Algebra Universalis 19, 1984, 208-216.

51. J. Jezek and T. Kepka: Notes on distributive groupoids. Commentatationes Math. Univ. Carolinae 24, 1983, 237-249.

52. A. Day and J. Jezek: The amalgamation property for varieties of lattices. Transactions of the AMS 286, 1984, 251-256.

53. J. Jezek and T. Kepka: Modular groupoids. Czechoslovak Math. J. 34, 1984, 477-487.

54. Elemetarily non-equivalent infinite partition lattices. Algebra Universalis 20, 1985, 132-133.

55. Nonfinitely based three-element idempotent groupoids. Algebra Universalis 20, 1985, 292-301.

56. Lattices isomorphic with their free powers. Order 2, 1985, 69-79.

57. J. Jezek and V. Trnkova: Varieties of groupoids with comprehensive products. Algebra Universalis 22, 1986, 142-153.

58. Subdirectly irreducible and simple Boolean algebras with endomorphisms. Proceedings, Charleston 1984. Universal Algebra and Lattice Theory. Lecture Notes in Math. 1149. Springer-Verlag. 150-162.

59. The lattice of equational theories. Part IV: Equational theories of finite algebras. Czechoslovak Math. J. 36, 1986, 331-341.

60. R. Freese, J. Jezek, J. B. Nation and V. Slavik: Singular covers in free lattices. Order 3, 1986, 39-46.

61. Equational theories of some almost unary groupoids. Commentatationes Math. Univ. Carolinae 27, 1986, 421-433.

63. J. Jezek and R. Quackenbush: Directoids: Algebraic models of up-directed sets. Algebra Universalis 27, 1990, 49-69.

65. J. Jezek and T. Kepka: Varieties of groupoids determined by short linear identities. Czechoslovak Math. J. 39, 1989, 644-658.

66. J. Jezek and V. Slavik: Free lattices over join-trivial partial lattices. Algebra Universalis 27, 1990, 10-31.

67. Minimal bounded varieties. Commentatationes Math. Univ. Carolinae 29, 1988, 261-265.

73. J. Jezek and R. Quackenbush: Minimal clones of conservative functions. International J. of Algebra and Computation 5, 1995, 615-630.

Please note that the following papers are often preprints, not final versions of the articles.

62. J. Jezek and R. McKenzie: Definability in the lattice of equational theories of semigroups. Semigroup Forum 46, 1993, 199-245 .64. J. Jezek and G. McNulty: Bounded and well-placed theories in the lattice of equational theories. Algebra Universalis 26, 1989, 311-331.

68. J. Jezek and V. Slavik: Free lattices over halflattices.Commentatationes Math. Univ. Carolinae 30, 1989, 203-211. (missing Figures 1 and 2)

69. J. Jezek and T. Kepka: Notes on the number of associative triples. Acta Universitatis Carolinae 31, 1990, 15-19.

70. J. Jezek, P. Pudlak and J. Tuma: On equational theories of semilattices with operators. Bull. Austral. Math. Soc. 42, 1990, 57-70.

71. On representable mappings of semigroups into cardinals. Rivista di Matematica Pura ed Applicata 6, 1990, 99-103.

72. J. Jezek and R. Quackenbush: The top of the lattice of clones of quasiprojections.

74. Subdirectly irreducible semilattices with one automorphism. Semigroup Forum 43, 1991, 178-186.

75. J. Jezek, N. Newrly and J. Tuma: Remarks on equational theories of semilattices with operators. Commentatationes Math. Univ. Carolinae 31, 1990, 415-425. (Missing Figures 1 and 2)

76. J. Jezek and T. Kepka: Medial division groupoids. Proceedings of the American Mathematical Society 119, 1993, 423-426.

78. R. Freese, J. Jezek and J. B. Nation: Term rewrite systems for lattices. J. Symbolic Computation 16, 1993, 279-288.

79. J. Jezek and G. F. McNulty: Finite axiomatizability of congruence rich varieties. Algebra Universalis 34, 1995, 191-213.

80. J. Jezek and G. F. McNulty: The existence of finitely based lower covers for finitely based equational theories. J. Symbolic Logic 60, 1995, 1242-1250.

81. J. Jezek and G. F. McNulty: Perfect bases for equational theories. J. Symbolic Computation 19, 1995, 489-505.

82. J. Jezek and T. Kepka: Self-distributive groupoids of small orders. Czechoslovak Math. J. 47, 1997, 463-468.

83. J. Jezek and T. Kepka: Bijective reflexions and coreflexions of commutative unars. Acta Universitatis Carolinae 37/1, 1996, 31-40.

85. J. Jezek and T. Kepka: Groupoids and the associative law XII (Representable cardinal functions). Acta Universitatis Carolinae 37/1, 1996, 41-62.

86. Enumerating left distributive groupoids. Czechoslovak Math. J. 47, 1997, 717-727.

87. A note on finite sets of terms closed under subterms and unification. Commentatationes Math. Univ. Carolinae 37, 1996, 655-656.

88. Some decidable congruences of free monoids. Czechoslovak Math. J. 49, 1999, 475-480.

89. J. R. Cho, J. Jezek and T. Kepka: Paramedial groupoids. Czechoslovak Math. J. 49, 1999, 277-290.

90. J. Jezek and T. Kepka: The equational theory of paramedial cancellation groupoids. Czechoslovak Math. J. 50, 2000, 25-34.

91. J. Jezek and T. Kepka: Linear equational theories and semimodule representations. International J. of Algebra and Computation 8 (1998), 599-615.

92. J. Jezek and V. Slavik: Incomparably contiunable sets of semilattices. Mathematica Bohemica 125, 2000, 135-137.

93. J. Jezek and V. Slavik: Random posets, lattices, and lattice terms. Mathamtica Bohemica 125, 2000, 129-133.

94. A decidable equational theory with undecidable membership problem for free algebras. Algebra Universalis 40, 1998, 497-499.

95. J. Jezek, P. Markovic, M. Maroti and R. McKenzie: Equations of tournaments are not finitely based. Discrete Mathematics 211 (2000), 243-248.

96. J. Jezek, P. Markovic, M. Maroti and R. McKenzie: The variety generated by tournaments. Acta Universitatis Carolinae 40/1, 1999, 21-41.

97. R. El Bashir, J. Jezek and T. Kepka: Simple zeropotent paramedial groupoids are balanced. Czechoslovak Math J. 50 (2000), 397-399.

98. J. R. Cho, J. Jezek and T. Kepka: Simple paramedial groupoids. Czechoslovak Math. J. 49, 1999, 391-399.

99. R. Freese, J. Jezek and J. B. Nation: Lattices with large minimal extensions. Algebra Universalis 45, 2001, 221-309.

100. J. Jezek and R. McKenzie: The variety generated by equivalence algebras. Algebra Universalis 45, 2001, 211-219.

101. J. Jezek and M. Maroti: Membership problems for finite entropic groupoids. (To appear).

102. J. Jezek and T. Kepka: Left distributive semigroups. Part D1 of Selfdistributive grupoids. Université de Caen CNRS ESA 6081. Rapport de recherche 1999-26. (See also the more recent version.)

103. Thermal grupoids. Czechoslovak Math J. 52, 2002, 705-716.

104. Three-variable equations of posets. Czechoslovak Math. J. 52, 2002, 811-816.

105. J. Jezek and V. Slavik: Cogruence lattices of finite chains with endomorphisms. Mathematica Bohemica 126, 2001, 737-744.

106. R. Freese, J. Jezek, P. Jipsen, P. Markovic, M. Maroti, R. McKenzie: The variety generated by order algebras. Algebra Universalis 47, 2002, 103-138.

107. Constructions over tournaments. Czechoslovak Math. J. 53, 2003, 413-428.

108. M. Fossorier, J. Jezek, J. B. Nation and A. Pogel: Ordinary graphs and subplane decompositions. Discrete Math. 282, 2004, 137-148.

109. One-element extensions in the variety generated by tournaments. Czechoslovak Math J. 54, 2004, 233-246.

110. A note on idempotent modifications of groups. Czechoslovak Math. J. 54, 2004, 229-231.

111. J. Jezek and T. Kepka: The factor of a subdirectly irreducible algebra through its monolith. Algebra Universalis 47, 2002, 319-327.

112. J. Jezek, M. Maroti and R. McKenzie: Quasiequational theories of flat algebras. Czechoslovak Math. J. 55, 2005, 665-675.

113. The ordering of commutative terms. Czechoslovak Math. J. 56, 2006, 133-154.

114. P. Dapic, J. Jezek, P. Markovic, R. McKenzie and D. Stanovsky: Star-linear equational theoreis of groupoids. Algebra Universalis 56, 2007, 357-397.

115. J. Jezek, P. Markovic and D. Stanovsky: Homomorphic images of finite subdirectly irreducible unary algebras. Czechoslovak Math. J. 57, 2007, 671-677.

116. J. Jezek and V. Slavik: Compact elements in the lattice of varieties. Mathematica Bohemica 130, 2005, 107-110.

117. J. Jezek and T. Kepka: Selfdistributive groupoids Part D1: Left distribudive semigroups. Acta Universitatis Carolinae 47, 2006, 15-16.

118. Slim groupoids. Czechoslovak Math. J. 57, 2007, 1275-1288.

119. Varieties of idempotent slim groupoids. Czechoslovak Math. J. 57, 2007, 1289-1309.

120. J. Jezek, V. Flaska, T. Kepka and J. Kortelainen: Transitive closures of binary relations I. Acta Universitatis Carolinae 48, 2007, 55-69.

121. J. Jezek, V. Flaska, T. Kepka: Transitive closures of binary relations II. Acta Universitatis Carolinae 48, 2007, 71-80.

122. J. Jezek, V. Flaska, T. Kepka: Transitive closures of binary relations II. Acta Universitatis Carolinae 49, 2008, 25-31.

123. W. Dziobiak, J. Jezek and R. McKenzie: Avoidable structures, I: Finite ordered sets. Algebra Universalis 60, 2009, 247-258.

124. W. Dziobiak, J. Jezek and R. McKenzie: Avoidable structures, II: Finite distributive lattices and nicely-structured ordered sets. Algebra Universalis 60, 2009, 259-291.

125. J. Jezek and R. McKenzie: Definability in substructure orderings, I: finite semilattices. Algebra Univesalis 61, 2009, 59-75.

126. J. Jezek and R. McKenzie: Definability in substructure orderings, II: finite ordered sets. Order 27, 2010, 115-145.

127. J. Jezek and R. McKenzie: Definability in substructure orderings, III: finite distributive lattices. Algebra Univesalis 61, 2009, 283-300.

128. J. Jezek and R. McKenzie: Definability in substructure orderings, IV: finite lattices. Algebra Univesalis 61, 2009, 301-312.

129. J. Jezek, T. Kepka and P. Nemec: Commutative semigroups that are nil of index 2 and have no irreducible elements. Math. Bohemica 133, 2008, 1-7.

130. J. Jezek, T. Kepka and M. Maroti: The endomorphism semiring of a semilattice. Semigroup Forum 78, 2009, 21-26.

131. J. Jezek and T. Kepka: The semiring of 1-preserving endomorphisms of a semilattice. Czechoslovak Math. J. 59, 2009, 999-1003.

132. W. Dziobiak, J. Jezek and M. Maroti: Minimal varieties and quasivarieties of semilattices with one automorphism. Semigroup Forum 78, 2009, 253-261.

133. P. Dapic, J. Jezek and P. Markovic: Star-quasilinear equational theories of groupoids. Studia Sci. Math. Hungar. 47, 2010, 267-288.

134. An algorithm for free algebras. (To appear in Commentatationes Math. Univ. Carolinae).

135. J. Jezek and T. Kepka Finitely generated commutative division semirings. Acta Universitatis Carolinae. 51, 2010, 3–28.

136. J. Jezek, V. Kala and T. Kepka: Finitely generated algebraic structures with various divisibility conditions. Forum Mathematicum. Published online 2010.

137. J. Jezek and T. Kepka: A note on uniserial loops. Commentationes Math. Univ. Carolinae 51, 2010, 263-265.

138. J. Jezek: Definability of equational theories of commutative grupoids. Czechoslovak Math. J. 62, 2012, 305-333.

14. Algebraicity of endomorphisms of some relational structures. Acta Fac. Rerum Nat. Univ. Comenianae Math. Special number, 1975, 17-18.

84. A. Drapal, J. Jezek and T. Kepka: Groupoids and the associative law IX. (Associative triples in some classes of groupoids). Acta Universitatis Carolinae 38/1, 1997, 39-52.