1. Batzli, G.O., R.G. White, and F.L. Bunnell. (1981). Herbivory: A strategy of tundra consumers. In: Tundra Ecosystems: a Comparative Analysis: International Biological Program, L.C. Bliss, O.W. Heal, and J.J. Moore, eds. Cambridge University Press, Cambridge, pp. 359–375.
2. Batzli, G.O., R.G. White, S.F. MacLean, F.A. Pitelka, and B.D. Collier. (1980). The herbivore-based trophic system. In: An Arctic Ecosystem: The Coastal Tundra at Barrow, Alaska, J. Brown, P.C. Miller, L.L. Tieszen, and F.L. Bunnell, eds. Dowden Hutchinson & Ross, Stroudsburg, pp. 335–410.
3. Bray, R.J. (1964). Primary consumption in three forest canopies. Ecology 45:165–167.
4. Brown, B.J. and J.J. Ewel. (1987). Herbivory in complex and simple tropical successional ecosystems. Ecology 68:108–116.
5. Bunderson, W.T. (1986). Primary production and energetic relationships of wild and domestic ungulate communities in African ecosystems. In: Rangelands: A Resource under Siege, P.J. Joss, P.W. Lynch, and O.B. Williams, eds. Australian Academy of Sciences, Canberra, pp. 397–401.