Gottlieb, L.D. (1973). "Genetic Differentiation, Sympatric Speciation, and the Origin of a Diploid Species of Stephanomeria". American Journal of Botany. 60 (6): 545–553. doi:10.2307/2441378. JSTOR2441378.
jstor.org
Gottlieb, L.D. (1973). "Genetic Differentiation, Sympatric Speciation, and the Origin of a Diploid Species of Stephanomeria". American Journal of Botany. 60 (6): 545–553. doi:10.2307/2441378. JSTOR2441378.
Gould, S. J. (1983). "The hardening of the Modern Synthesis" In Marjorie Grene, ed., Dimensions of Darwinism. Cambridge UK: Cambridge University Press, pp. 71-93.