Voir la notice de l'article provenant de la source Mathematicac Balkanica website
@article{MABA_1991_5_2_a0, author = {Shi Mingquan}, title = {Some {Results} of the {\ensuremath{\pi}-Semigroups}}, journal = {Mathematica balkanica}, pages = {81}, publisher = {mathdoc}, volume = {5}, number = {2}, year = {1991}, url = {http://geodesic.mathdoc.fr/item/MABA_1991_5_2_a0/} }
Shi Mingquan. Some Results of the π-Semigroups. Mathematica balkanica, Tome 5 (1991) no. 2, p. 81. http://geodesic.mathdoc.fr/item/MABA_1991_5_2_a0/