Perhaps you should try some spelling variations:
country's integration » countries integration, countries integrating, country integrated
integration theory » integration through, information theory, innovation theory
irrigation scheme » irrigation systems
supply country's » supply contracts, supply contract
farm irrigation » scale irrigation, canal irrigation
supply farm » supply from, support farm

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

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