中国科学院数学与系统科学研究院期刊网
AMS
On Green’s Relations, 20-regularity and Quasi-ideals in Γ-semigroups
Kostaq HILA, Jani DINE
Acta Mathematica Sinica . 2013, (3): 609 -624 .  DOI: 10.1007/s10114-012-0027-1