@article{10_1017_S2040618500033360,
     author = {Preston, G. B.},
     title = {The {Structure} of {Normal} {Inverse} {Semigroups}},
     journal = {Glasgow mathematical journal},
     pages = {1--9},
     year = {1956},
     volume = {2},
     number = {1},
     doi = {10.1017/S2040618500033360},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S2040618500033360/}
}