Gould, S. J. (1982). "The uses of heresey; an introduction to Richard Goldschmidt's The Material Basis of Evolution." pp. xiii-xlii. New Haven: Yale University Press.
France Dufresne, Paul D. N. Herbert (1994). "Hybridization and origins of polyploidy". Proceedings of the Royal Society. JSTOR49988.Falta a |url= (Axuda); |data-acceso= require |url= (Axuda)