@article{10_1017_S001708950000954X,
     author = {Petrich, Mario},
     title = {The congruence lattice of an ideal extension of semigroups},
     journal = {Glasgow mathematical journal},
     pages = {39--50},
     year = {1993},
     volume = {35},
     number = {1},
     doi = {10.1017/S001708950000954X},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S001708950000954X/}
}