[1] Sedlock J. T.:
Green's relations on a periodic semigroup. Czech. Math. J., 19 (1969), 318 - 323.
MR 0244426 |
Zbl 0214.03504
[3] Pondělíček В.:
On a certain relation for closure operations on a semigroup. Czech. Math. J., 20 (1970), 220-231.
MR 0260905
[5] Petrich M.:
Semigroups certain of whose subsemigroups have identities. Czech. Math. J., 16 (1966), 186-198.
MR 0200370 |
Zbl 0143.03203
[6] Pondělíček В.: Right prime ideals and maximal right ideals in semigroup. Mat. Časopis Slovensk. Akad. Vied (to appear).