Perhaps you should try some spelling variations:
integration theories » integration theorems, integrationstheorie 2, integration theory
irrigation system » irrigation systems, irrigation water, irrigation scheme
fare integration » trade integration, die integration
canal irrigation » scale irrigation
supply canal » supply canada, supply annual, supply china
supply fare » supply farm, supply case, supply figure

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply fare integration theories. ) OR ( supply canal irrigation system. ))~.
• Adding a wildcard symbol may retrieve word variants: (( supply fare integration theories. ) or ( supply canal irrigation system. ))*.