Refworks: Do you want to use it? Advanced Tutorials helpful?
Research Techniques to consider:
Look up any book title on bibliography and see what subject headings were assigned.
Use Worldcat (Firstsearch) Click on them to find more.
LC Headings I found this way
Tropical Crops—subdivide physiology
Agronomy-Tropics subdivide history
Cotton Growing - subdivide
Use a known author or author’s work and find out who has cited that work.
Best place to start: Web Of Science.
Databases to Look at:
Proquest Agricultural Collection
Proquest Environmental Science Collection
Proquest Sociological Abstracts
Proquest Worldwide Political Science Abstracts
Web of Science
Springer Link (Full Text ebooks and journals from this publisher) try peasants farmers and scientists as a start
Taylor and Francis
Wiley Online Library