@article{SF_1983__27_134623,
     author = {A.N. Petrov},
     title = {Some embedding theorems in varieties of semigroups.},
     journal = {Semigroup forum},
     pages = {201--222},
     year = {1983},
     volume = {27},
     zbl = {0518.20057},
     url = {http://geodesic.mathdoc.fr/item/SF_1983__27_134623/}
}