On nonplanar graphs with the minimum number of vertices and a given girth.
(English).Commentationes Mathematicae Universitatis Carolinae,
vol. 11
(1970),
issue 1,
pp. 9-17
[1] KURATOWSKI G.: Sur le problème des courbes gauches en topologie. Fund. Math. 15-16 (1930), 271-283.
[2] VOSS H.-J.: Some properties of graphs containing $k$ independent circuits. Theory of Graphs, Proc. Colloq. Tihany, Hungary, 1966, Akadémiai Kiadó, Budapest (1968), 321-332. MR 0241319