1997, Rosamond L. Naylor, Paul R. Ehrlich, Chapter 9: Natural Pest Control Services and Agriculture, Gretchen Daily (editor), Nature's Services: Societal Dependence On Natural Ecosystems, page 156
2000, E. M. Craddock, “1: Speciatio Processes in the Adaptive Radiation of Hawaiian Plants and Animals”, in Max K. Hecht, Ross J. MacIntyre, Michael T. Clegg, editors, Evolutionary Biology, volume 31, page 20