[1] J. R. Cho, J. Ježek and T. Kepka: 
Paramedial groupoids. (Preprint). 
MR 1692473 
[2] J. Ježek and T. Kepka: Equational theory of paramedial groupoids. (Preprint).
[3] J. Ježek and T. Kepka: 
Medial groupoids. Rozpravy ČSAV 93/2 (1983). 
MR 0734873 
[4] J. Ježek and T. Kepka: 
Linear equational theories and semimodule representations. (Preprint). 
MR 1675018 
[5] J. Ježek and T. Kepka: 
Simple semimodules over commutative semirings. Acta Sci. Math. Szeged 46 (1983), 17–27. 
MR 0739018