W. D. Wallis served as a Professor of Mathematics at Southern Illinois University, Carbondale, for 24 years up until his retirement in 2009. Before that he taught for 15 years at the University of Newcastle, Australia, and for 4 years at La Trobe University, Australia. His main areas of research have been in Combinatorial Mathematics and Graph Theory. He has also published some work in Computer Science and in Algebra. He has authored or co-authored fourteen books on Mathematics, together with some second editions, and edited nine books. He has published 268 research articles and book chapters.