@article{GDZPPN00126558X, title = {Some abstract properties of semigroups appearing in superconformal theories.}, journal = {Semigroup forum}, volume = {54}, year = {1997}, pages = {253-260}, zbl = {0879.58009}, url = {http://dml.mathdoc.fr/item/GDZPPN00126558X} }
Duplij, S. Some abstract properties of semigroups appearing in superconformal theories.. Semigroup forum, Tome 54 (1997) pp. 253-260. http://gdmltest.u-ga.fr/item/GDZPPN00126558X/