@article{SF_1993__46_1_135210,
     author = {D.V. Dekov},
     title = {Free products with amalgamation of semigroups.},
     journal = {Semigroup forum},
     pages = {54--61},
     publisher = {mathdoc},
     volume = {46},
     number = {1},
     year = {1993},
     zbl = {0802.20048},
     url = {http://geodesic.mathdoc.fr/item/SF_1993__46_1_135210/}
}