Perhaps you should try some spelling variations:
small farmers » small firms
yang yang » wang yang, wang yan
jie small » live small, wine small, one small
using dem » using dhm, using deep, using ddms
using dea » using dna, using delta, using ideal
yang jie » yang jin, yang di, yang jui
yu yang » du yang, yi yang, yu fang

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((yang yang) or (yu yang)) yang jie small farmers ((using dem) OR (using dea)) bei ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((yang yang) OR (yu yang)) yang jie small farmers ((using dem) OR (using dea)) bei ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((yang yang) or (yu yang)) yang jie small farmers ((using dem) OR (using dea)) bei ;*".