J. J.  Wiens, ?Polymorphism in Systematics and Comparative Biology?, Annual Review of Ecology and Systematics, vol. 30, pp. 327-362, 1999.

S. G.  Weller and Sakai, A. K., ?Using Phylogenetic Approaches for the Analysis of Plant Breeding System Evuolution?, Annual Review of Ecology and Systematics, vol. 30, pp. 167-199, 1999.

N. C.  Ellstrand, Prentice, H. C., and Hancock, J. F., ?Gene Flow and Introgression from Domesticated PLants into their Wild Relatives?, Annual Review of Ecology and Systematics, vol. 30, pp. 539-563, 1999.