1. Berendse F (1979) Competition between plant populations with different rooting depths. I. Theoretical considerations. Oecologia (Berlin) 43:19?26
2. Bykov BA (1974) Fluctations in the semidesert and desert vegetation of the Ruranian plain. In: R Knapp (ed), Handbook of vegetation science part 8. The Hague: Dr. W. Junk, pp 243?251
3. Chiariello NR (1981) The adaptive significance of phenology and allocation in seasonal races of a grassland annual. Ph.D. Thesis, Stanford University, Stanford CA
4. Eickmeier WG (1978) Photosynthetic pathway distributions along an aridity gradient in Big Bend National Park, and implications for enhanced resource partitioning. Photosynthetica 12:290?297
5. Gulmon SL (1979) Competition and coexistence in three annual grass species. Am Midl Naturalist 101:403?416