@article{104926, author = {Cor P. Baayen and Zden\v ek Hedrl\'\i n}, title = {On the product and sum of a system of transformation semigroups}, journal = {Commentationes Mathematicae Universitatis Carolinae}, volume = {004}, year = {1963}, pages = {29-42}, zbl = {0116.25601}, mrnumber = {0159895}, language = {en}, url = {http://dml.mathdoc.fr/item/104926} }
Baayen, Cor P.; Hedrlín, Zdeněk. On the product and sum of a system of transformation semigroups. Commentationes Mathematicae Universitatis Carolinae, Tome 004 (1963) pp. 29-42. http://gdmltest.u-ga.fr/item/104926/
Two theorems concerning common fixed points of commutative mappings, CMUC, 3, 2 (1962). (1962) | MR 0159896