1. Bell, E.A., and Janzen, D.H., Nature229 (1971) 136.
2. Janzen, D.H., Evolution23 (1969) 1.
3. Evans, G.C., J. appl. Ecol.13 (1976) 1.
4. Hartshorn, G.S., in: Tropical Trees as Living Systems, p. 617. Eds P.B. Tomlinson and M.H. Zimmerman. Cambridge University Press, Cambridge, Mass., 1978.
5. McKay, D., Waterman, P.G., Mbi, C.N., Gartlan, V.S., and Struhsaker, T.T., Science202 (1978) 61.