@article{SF_1996__52_3_135462,
     author = {M. Ciric and S. Bogdonovic},
     title = {Identities over the two-element alphabet.},
     journal = {Semigroup forum},
     pages = {365--380},
     publisher = {mathdoc},
     volume = {52},
     number = {3},
     year = {1996},
     url = {http://geodesic.mathdoc.fr/item/SF_1996__52_3_135462/}
}