1. Agresti A (1990) Categorical Data Analysis. New York: John Wiley
2. Allen ON, Allen EK (1981) The Leguminosae. A Sourcebook of Characteristics, Uses and Nodulation. London: Macmillan
3. Archer BL, Audley BG (1973) Rubber, gutta percha and chicle. Pp 310?343in Miller LP (ed) Phytochemistry. Vol. II: Organic Metabolites. New York: Van Nostrand Reinhold
4. Carlquist S (1958) Anatomy of Guayana Mutisieae. II. Mem NY Bot Gdn 10:157?184
5. Coley PD, Bryant JP, Chapin III FS (1985) Resource availability and plant antiherbivore defense. Science 230:895?899