[3] P. Erdös, A. Rényi, V.T. Sós:
On a problem of Graph Theory. Studia Scientiarum Mathematicarum Hungarica 1 (1966), 215–235.
MR 0223262
[4] O. Frank, F. Harary, M. Plantholt:
The line-distinguishing chromatic number of a graph. Ars Combinatoria 14 (1982), 241–252.
MR 0683991
[5] F. Harary:
Graph Thery. Addison-Wesley, Reading, 1969.
MR 0256911
[6] F. Regonati, N. Zagaglia Salvi:
Minimal semicomplete graphs. to appear in J. Combin., Inform. and System Sci.
MR 1358644