Perhaps you should try some spelling variations:
integration theories » integration theorems, integrationstheorie 2, integration theory
irrigation system » irrigation systems, irrigation water, irrigation scheme
grid irrigation » grain irrigation, drip irrigation, gray irrigation
supply grid » supply crowd, supply great, support grid
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 grid irrigation system. ) or ( ((supply trade) OR (supply case)) integration theories. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply grid irrigation system. ) OR ( ((supply trade) OR (supply case)) integration theories. )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( supply grid irrigation system. ) or ( ((supply trade) OR (supply case)) integration theories. ))".
• Adding a wildcard symbol may retrieve word variants: (( supply grid irrigation system. ) or ( ((supply trade) OR (supply case)) integration theories. ))*.