Ramsey's theorem and self-complementary graphs. - Vasek Chvátal; Paul Erdös; Z. Hedrlín (Discret. Math., 1972)

A Game of Composing Binary Relations. - Pavel Goralcik; Z. Hedrlín; Václav Koubek; V. Ryslinková (RAIRO Theor. Informatics Appl., 1982)