@article{SF_1976__12_134171,
     author = {M. Petrich},
     title = {Rings and {Semigroups} {(Book} {Review} by {E.}  {Behrens).}},
     journal = {Semigroup forum},
     pages = {185--187},
     publisher = {mathdoc},
     volume = {12},
     year = {1976},
     url = {http://geodesic.mathdoc.fr/item/SF_1976__12_134171/}
}