Perhaps you should try some spelling variations:
integration theories » integration theory, integration through, integration efforts
irrigation schemes » irrigation scheme, irrigation systems
chain integration » trade integration, data integration, grid integration
curve irrigation » large irrigation, crop irrigation, surface irrigation

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 chain integration theories. ) OR ( supply curve irrigation schemes. ))~.
• Adding a wildcard symbol may retrieve word variants: (( supply chain integration theories. ) or ( supply curve irrigation schemes. ))*.