@article{SF_1974__9_134058,
     author = {J.A. Gerhard},
     title = {Injectives in equational classes of  idempotent semigroups.},
     journal = {Semigroup forum},
     pages = {36--53},
     publisher = {mathdoc},
     volume = {9},
     year = {1974},
     zbl = {0289.20038},
     url = {http://geodesic.mathdoc.fr/item/SF_1974__9_134058/}
}