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Tiling with Dominoes

Nathan Mendelsohn (mendel @cc.umanitoba.ca) was born on April 14, 1917, and all of his education was obtained in Toronto, Canada. His early publications were in the areas of geometry and number theory. He later changed his research to combinatorics, specializing in block designs, orthogonal arrays, and bipartite graphs. At age 86, he still does research (although he claims to have slowed down considerably).