@article{10_1017_S0017089599970866,
     author = {Petrich, Mario},
     title = {The kernel relation for an extension of completely 0-simple semigroups},
     journal = {Glasgow mathematical journal},
     pages = {211--230},
     year = {1999},
     volume = {41},
     number = {2},
     doi = {10.1017/S0017089599970866},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089599970866/}
}