@article{SF_1986__34_134845,
     author = {B. Piochi},
     title = {Solvability in inverse semigroups.},
     journal = {Semigroup forum},
     pages = {287--304},
     publisher = {mathdoc},
     volume = {34},
     year = {1986},
     zbl = {0604.20058},
     url = {http://geodesic.mathdoc.fr/item/SF_1986__34_134845/}
}