1. Stewart Wilcox, Complementation in the group of units of matrix rings, Bull. Austral. Math. Soc. 70 (2004), no. 2, 223–227.[MR]
  2. Stewart Wilcox, Reduction of the Hall-Paige conjecture to sporadic simple groups, J. Algebra 321 (2009), no. 5, 1407–1428.[MR]