@article{PIM_1989_N_S_45_59_a2,
     author = {Ivan Gutman},
     title = {Perfect {Matchings} in a {Class} of {Bipartite} {Graphs}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {11 },
     publisher = {mathdoc},
     volume = {_N_S_45},
     number = {59},
     year = {1989},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PIM_1989_N_S_45_59_a2/}
}