Perhaps you should try some spelling variations:
deeper integration » deep integration, der integration, merger integration
integration theory » integration through, information theory, innovation theory
furrow irrigation » farm irrigation, crop irrigation, flood irrigation
irrigation system » irrigation systems, irrigation water, irrigation scheme
support furrow » support from, support follow

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 deeper integration theory. ) OR ( support furrow irrigation system. ))~.
• Adding a wildcard symbol may retrieve word variants: (( supply deeper integration theory. ) or ( support furrow irrigation system. ))*.