1991
“Traditional Agroforestry Practices In Zimbabwe”. Agroforestry Systems 14 (2): 99-111. doi:10.1007/BF00045726. http://link.springer.com/article/10.1007/BF00045726.
. 1991. 1990
“The Tragedy Of The Commons: Twenty-Two Years Later”. Human Ecology 18 (1): 1-19. doi:10.1007/BF00889070. http://dx.doi.org/10.1007/BF00889070.
. 1990.