Perhaps you should try some spelling variations:
crop adoption » erp adoption, crop adaptation
era adoption » ema adoption, esa adoption, a adoption
energy crop » energy crops
energy erec » energy ee, energy effect, energy esecom
energy erp » energy ep, energy e, energy end
energy era » energy e, energy end

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((((\\"energy crop adoption\\") or (\\"((energy erp) OR (energy erec)) adoption\\"))) or (\\"energy era adoption\\"))\"".
• Removing quotes may allow a broader search: (((( energy crop adoption ) or ( ((energy erp) OR (energy erec)) adoption ))) or ( energy era adoption )).