Generalised Mycielski graphs, signature systems, and bounds on chromatic numbers. - Gord Simons; Claude Tardif; David L. Wehlau (J. Comb. Theory B, 2017)

Topologically 4-chromatic graphs and signatures of odd cycles. - Gord Simons; Claude Tardif; David L. Wehlau (J. Graph Theory, 2020)