On minimal digraphs with given girth, Proceedings of the Ninth Southeastern Conference on Combinatorics, Graph Theory, and Computing, pp.181-187, 1978. ,
Cycles in Multipartite Tournaments, Journal of Combinatorial Theory, Series B, vol.62, issue.2, pp.363-366, 1994. ,
DOI : 10.1006/jctb.1994.1075
A note on short cycles in digraphs, pp.103-107, 1987. ,
A summary of results and problems related to the Caccetta-Häggkvist conjecture, preprint ,
Vertex deletion and cycles in multipartite tournaments, Discrete Math, pp.769-779, 1999. ,
DOI : 10.1016/s0012-365x(99)90145-0
URL : http://doi.org/10.1016/s0012-365x(99)90145-0
The 2-linkage problem for acyclic digraphs, Discrete Math, pp.73-87, 1985. ,