@article{MASLO_1981__31_2_a5,
     author = {Plesn{\'\i}k, J\'an},
     title = {A bound for the {Steiner} tree problem in graphs},
     journal = {Mathematica slovaca},
     pages = {155--163},
     publisher = {mathdoc},
     volume = {31},
     number = {2},
     year = {1981},
     mrnumber = {611627},
     zbl = {0458.05027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1981__31_2_a5/}
}