Perhaps you should try some spelling variations:
irrigation system » irrigation systems, irrigation water, irrigation scheme
grid irrigation » drip irrigation, syria irrigation, crop irrigation
supply trade » supply side
support grid » support agri, support grant, support group
supply case » supply cost, supply chain, supply curve

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((supply trade) OR (supply case)) information theory. ) or ( support grid irrigation system. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((supply trade) OR (supply case)) information theory. ) OR ( support grid irrigation system. )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((supply trade) OR (supply case)) information theory. ) or ( support grid irrigation system. ))".
• Adding a wildcard symbol may retrieve word variants: (( ((supply trade) OR (supply case)) information theory. ) or ( support grid irrigation system. ))*.