@article{MASLO_1978__28_1_a5,
     author = {Sudolsk\'y, Mari\'an},
     title = {A generalization of the friendship theorem},
     journal = {Mathematica slovaca},
     pages = {57--59},
     publisher = {mathdoc},
     volume = {28},
     number = {1},
     year = {1978},
     mrnumber = {527774},
     zbl = {0366.05041},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1978__28_1_a5/}
}