@article{10_1017_S0017089500009022,
     author = {Bonzini, C. and Cherubini, A. and Piochi, B.},
     title = {The {Least} {Commutative} {Congruence} on a simple regular \ensuremath{\omega}-semigroup{\textdagger}},
     journal = {Glasgow mathematical journal},
     pages = {13--23},
     year = {1990},
     volume = {32},
     number = {1},
     doi = {10.1017/S0017089500009022},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500009022/}
}