[1] S, Schwarz: The ideal structure of C-semigroups. Czech. Math. J. 27 {102), 1977, 313-338. MR 0439961 | Zbl 0376.20038

[2] K. H, Kim-Butler S. Schwarz: The semigroups of circulant Boolean matrices. Czech. Math. J. 26 (101), 1976, 632-635. MR 0430121

[3] Š. Schwarz: A counting theorem in the semigroup of circulant Boolean matrices. Czech. Math. J. 27 (102), 1977, 504-510. MR 0457603 | Zbl 0382.15010

[4] Š. Schwarz: Semigroups containing maximal ideals. Math. Slovaca 28, 1978, 157-168. MR 0526854 | Zbl 0378.20047

[5] Š. Schwarz: Intersection of maximal ideals in semigroups. Semigroup Forum 12, 1976, 367-372. DOI 10.1007/BF02195942 | MR 0414760

[6] Š. Schwarz: A theorem on binary relations and infinite regular languages. Semigroup Forum 17, 1979, 307-316. MR 0532422 | Zbl 0425.20053

[7] Š. Schwarz: The Euler-Fermat theorem for the semigroup of circulant Boolean matrices. Czech. Math. J. 30 (105), 1980, 135-141. MR 0565916 | Zbl 0443.20053

[8] Š. Schwarz: Infinite products of doubly stochastic matrices. Acta Fac. Natur. Univ. Comenian (in print). Zbl 0521.15010