@article{SF_1986__33_134817,
     author = {J.L. Galbiati and M.L. Veronesi},
     title = {Congruences on semigroups which are perfect rectangular bands of inverse semigroups.},
     journal = {Semigroup forum},
     pages = {309--330},
     publisher = {mathdoc},
     volume = {33},
     year = {1986},
     zbl = {0584.20055},
     url = {http://geodesic.mathdoc.fr/item/SF_1986__33_134817/}
}