THE SIGN OF LESER-TRÉLAT - Czarnecki, D. B.; Rotstein, H.; O'Brien, T. J.; Lyall, I. G.; Hanna, M. J. D. (Blackwell Publishing Ltd, 1983)
http://dx.doi.org/10.1111/j.1440-0960.1983.tb00263.x
Keywords: WW-YZ