[1] M. Behzad G. Chartrand, L. Lesniak-Foster:
Graphs & Digraphs. Prindle, Weber & Schmidt, Boston, 1979.
MR 0525578
[2] D.C. Kay, G. Chartrand:
A characterization of certain ptolemaic graphs. Canad. J. Math. 17 (1965), 342-346.
MR 0175113 |
Zbl 0139.17301
[4] L. Nebeský:
Route systems and bipartite graphs. Czechoslovak Math. Journal 41 (116) (1991), 260-264.
MR 1105440