Perhaps you should try some spelling variations:
"supply scale irrigation schemes." » "supply scale irrigation scheme.", "supply scale irrigation systems.", "supply case irrigation schemes.", "supply scheme irrigation schemes.", "supply social irrigation schemes."
"supply factor integration theory." » "supply facto integration theory.", "supply sector integration theory.", "supply actor interaction theory.", "supply factor integration through.", "supply factor information theory.", "supply factor innovation theory.", "supply factors integration theory."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("supply scale irrigation schemes.") or ("supply factor integration theory."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply scale irrigation schemes.") OR ("supply factor integration theory."))*.
• Removing quotes may allow a broader search: (( supply scale irrigation schemes. ) or ( supply factor integration theory. ))*.