1993 - Long, C.R.; Pinto-Correia, C.; Duby, R.T.; Ponce de Leon, F.A.; Boland, M.P.; Roche, J.F. & Robl, J.M. Sperm aster formation and the cell cycle in monospermic and polyspermic cow zygotes. Molecular Reproduction and Development, 36: 23-32