@article{SM_1975_27_4_a1,
     author = {D. V. Znoiko},
     title = {Free products of networks and free symmetrizers of graphs},
     journal = {Sbornik. Mathematics},
     pages = {463--480},
     publisher = {mathdoc},
     volume = {27},
     number = {4},
     year = {1975},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1975_27_4_a1/}
}