@article{GDZPPN001263528, title = {Hyperassociative varieties of semigroups.}, journal = {Semigroup forum}, volume = {48}, year = {1994}, pages = {41-48}, zbl = {0806.20049}, url = {http://dml.mathdoc.fr/item/GDZPPN001263528} }
Denecke, K.; Koppitz, J. Hyperassociative varieties of semigroups.. Semigroup forum, Tome 48 (1994) pp. 41-48. http://gdmltest.u-ga.fr/item/GDZPPN001263528/