Perhaps you should try some spelling variations:
"support trade integration theories." » "support trade integration theory.", "support trade integration through.", "support trade integration efforts.", "export trade integration theories.", "support grant integration theories.", "import trade integration theories."
"supply water integration schemes." » "supply water irrigation schemes.", "supply water integration some.", "supply water integrating schemes.", "supply factor integration schemes.", "supply data integration schemes."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("support trade integration theories.") or ("supply water integration schemes."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("support trade integration theories.") OR ("supply water integration schemes.")).
• Removing quotes may allow a broader search: (( support trade integration theories. ) or ( supply water integration schemes. )).
• Adding a wildcard symbol may retrieve word variants: (("support trade integration theories.") or ("supply water integration schemes."))*.