Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
basin irrigation » drip irrigation, canal irrigation, farm irrigation
syria irrigation » africa irrigation, drip irrigation, surge irrigation
supply basin » supply asia, supply based, supply design
supply syria » supply africa, supply social, supply sierra

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( supply basin irrigation schemes. ) or ( supply syria irrigation schemes. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply basin irrigation schemes. ) OR ( supply syria irrigation schemes. )).
• Adding a wildcard symbol may retrieve word variants: (( supply basin irrigation schemes. ) or ( supply syria irrigation schemes. ))*.