Before revision: Gradient analysis of vegetation, Biological Review, 42, 207-264 More recent work includes a six year study of temporal and spatial yield stability over 11 years ( and references therein),Kaspar, T.C, Colvin, T.S., Jaynes, B., Karlen, D.L., James, D.E, Meek, D.W., 2003.
After revision: Kaspar et al., (2003),Gradient analysis of vegetation, Biological Review, 42, 207-264 More recent work includes a six year study of temporal and spatial yield stability over 11 years ( and references therein),Kaspar, T.C, Colvin, T.S., Jaynes, B., Karlen, D.L., James, D.E, Meek, D.W., 2003.