Hell, Pavel; Nešetřil, Jaroslav Homomorphisms of graphs and of their orientations. (English) Zbl 0375.05023 Monatsh. Math. 85, 39-48 (1978). MSC: 05C10 05C99 05C20 PDFBibTeX XMLCite \textit{P. Hell} and \textit{J. Nešetřil}, Monatsh. Math. 85, 39--48 (1978; Zbl 0375.05023) Full Text: DOI EuDML
Nešetřil, Jaroslav On symmetric and antisymmetric relations. (English) Zbl 0248.05119 Monatsh. Math. 76, 323-327 (1972). MSC: 05C25 05C20 03E20 20B25 PDFBibTeX XMLCite \textit{J. Nešetřil}, Monatsh. Math. 76, 323--327 (1972; Zbl 0248.05119) Full Text: DOI EuDML