Shulka, R. A note on radicals in factor semigroups. (Russian) Zbl 0131.01903 Mat.-Fyz. Čas., Slovensk. Akad. Vied 14, 297-299 (1964). PDFBibTeX XMLCite \textit{R. Shulka}, Mat.-Fyz. Čas., Slovensk. Akad. Vied 14, 297--299 (1964; Zbl 0131.01903) Full Text: EuDML
Shulka, R. On nilpotent elements, ideals and radicals of a semigroup. (Russian) Zbl 0131.01902 Mat.-Fyz. Čas., Slovensk. Akad. Vied 13, 209-221 (1963). PDFBibTeX XMLCite \textit{R. Shulka}, Mat.-Fyz. Čas., Slovensk. Akad. Vied 13, 209--221 (1963; Zbl 0131.01902) Full Text: EuDML