2012 Euler Medal award to Alexander Rosa
Alex Rosa is the international authority on many topics in combinatorial design theory, including Steiner triple systems, Steiner quadruple systems, labellings, cycle systems, and colourings. He has published more than 200 refereed journal papers, written a major research monograph on Triple Systems, and founded the leading Journal of Combinatorial Designs. His work has opened new fields of research, breaking new ground repeatedly. For decades, Alex has emphasized the elegance of new ideas, and has freely shared his knowledge and ideas with his younger colleagues. As one nominator says, he is a “master at constructing designs” and an “inspiration”.