Bier, Thomas; Zaguia, Imed Some inequalities for orderings of acyclic digraphs. (English) Zbl 1384.05089 Contrib. Discrete Math. 13, No. 1, 150-160 (2018). MSC: 05C20 06A05 06A06 06A07 PDFBibTeX XMLCite \textit{T. Bier} and \textit{I. Zaguia}, Contrib. Discrete Math. 13, No. 1, 150--160 (2018; Zbl 1384.05089)
Severino, Michael A short construction of highly chromatic digraphs without short cycles. (English) Zbl 1317.05079 Contrib. Discrete Math. 9, No. 2, 91-94 (2014). MSC: 05C20 05C15 68R10 PDFBibTeX XMLCite \textit{M. Severino}, Contrib. Discrete Math. 9, No. 2, 91--94 (2014; Zbl 1317.05079)