Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme
syria irrigation » africa irrigation, drip irrigation, surge irrigation
spate irrigation » scale irrigation, water irrigation, surge irrigation
support syria » support social, support agri
supply spate » supply system, supply side, supply water
systems. » system.

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

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