@article{10_4153_CMB_1977_040_5,
     author = {Jr., C. S. Johnson and McMorris, F. R.},
     title = {Commutative {Non-Singular} {Semigroups}},
     journal = {Canadian mathematical bulletin},
     pages = {263--265},
     year = {1977},
     volume = {20},
     number = {2},
     doi = {10.4153/CMB-1977-040-5},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1977-040-5/}
}