@article{CMH_1970__45_139429,
     author = {Gerhard Ringel and J.W.T. Youngs},
     title = {Das {Geschlecht} des vollst\"andigen dreif\"arbbaren {Graphen.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {152--158},
     publisher = {mathdoc},
     volume = {45},
     year = {1970},
     zbl = {0192.60507},
     url = {http://geodesic.mathdoc.fr/item/CMH_1970__45_139429/}
}