1987
“Peasant Agriculture And The Conservation Of Crop And Wild Plant Resources”. Conservation Biology 1 (1): 49-58. doi:10.1111/j.1523-1739.1987.tb00008.x. http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.1987.tb00008.x/abstract.
. 1987. 1988
Glossary Of Selected Terms In Sustainable Agriculture. Gatekeeper Series No. Sa6. London; Washington, DC: International Institute for Environment and Development, Sustainable Agriculture Programme. http://www.worldcat.org/oclc/19531919.
. 1988.