@article{GDZPPN001255789, title = {On algebraic closure and amalgamation of semigroups.}, journal = {Semigroup forum}, volume = {24}, year = {1982}, pages = {223-268}, zbl = {0528.20047}, url = {http://dml.mathdoc.fr/item/GDZPPN001255789} }
Belyaev, V.Y. On algebraic closure and amalgamation of semigroups.. Semigroup forum, Tome 24 (1982) pp. 223-268. http://gdmltest.u-ga.fr/item/GDZPPN001255789/