@article{10_1017_S0017089500004894,
     author = {Pastijn, Francis},
     title = {Essential normal and conjugate extensions of inverse semigroups},
     journal = {Glasgow mathematical journal},
     pages = {123--130},
     year = {1982},
     volume = {23},
     number = {2},
     doi = {10.1017/S0017089500004894},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500004894/}
}