@article{ELMA_1978__33_141213,
     author = {Egon Joachim},
     title = {Minimale nicht in die {Ringfl\"ache} einbettbare {Graphen.}},
     journal = {Elemente der Mathematik},
     pages = {57--61},
     publisher = {mathdoc},
     volume = {33},
     year = {1978},
     zbl = {0387.05006},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1978__33_141213/}
}