@article{SF_1984__30_134728,
     author = {J.A. Hildebrant},
     title = {The translational degree of a semigroup.},
     journal = {Semigroup forum},
     pages = {331--350},
     publisher = {mathdoc},
     volume = {30},
     year = {1984},
     zbl = {0536.20039},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__30_134728/}
}