Perhaps you should try some spelling variations:
"supply national integration theories." » "supply regional integration theories.", "supply national innovation theories.", "supply national integrity theories.", "supply national integration theory.", "supply national integration through.", "supply national integration efforts."
"supply crowd integration schemes." » "supply crowd irrigation schemes.", "supply crowd integration some.", "supply grid integration schemes.", "supply trade integration schemes.", "supply chain integration schemes.", "supply growth integration schemes.", "supply cost integration schemes.", "supply how integration schemes."

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 crowd integration schemes.") OR ("supply national integration theories."))~.
• Removing quotes may allow a broader search: (( supply crowd integration schemes. ) or ( supply national integration theories. ))~.
• Adding a wildcard symbol may retrieve word variants: (("supply crowd integration schemes.") or ("supply national integration theories."))*.