1. Abrahamson, W. G., G. Melika, R. Scrafford & G. Csoka, 1998. Gall-inducing insects provide insights into plant systematic relationships. American Journal of Botany 85: 1159–1165.
2. Adler, L. S., R. Karban & S. Y. Strauss, 2001. Direct and indirect effects of alkaloids on plant fitness via herbivory and pollination. Ecology 82: 2032–2044.
3. Agrawal, A. A., 2000. Host range evolution: adaptation and trade-offs in fitness of mites on alternative hosts. Ecology 81: 500–508. Agrawal, A. A., 2001. Phenotypic plasticity in the interactions and evolution of species. Science 294: 321–326.
4. Agrawal, A. A., S. Tuzun & E. Bent (eds), 1999. Induced Plant Defenses Against Pathogens and Herbivores: Biodiversity, Ecology, and Agriculture. APS Press, St. Paul, MN.
5. Arnold, M. L., 1997. Natural Hybridization and Evolution. Oxford University, New York.