Perhaps you should try some spelling variations:
"support grid irrigation schemes." » "support grid irrigation scheme.", "support grid irrigation systems.", "support grain irrigation schemes.", "support drip irrigation schemes.", "support gray irrigation schemes.", "support agri irrigation schemes.", "support grant irrigation schemes.", "support group irrigation schemes."
"supply crowd information theory." » "supply road information theory.", "supply crop information theory.", "supply card information theory.", "supply growth information theory.", "supply cost information theory.", "supply from information theory."

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: (("support grid irrigation schemes.") OR ("supply crowd information theory."))~.
• Removing quotes may allow a broader search: (( support grid irrigation schemes. ) or ( supply crowd information theory. ))~.
• Adding a wildcard symbol may retrieve word variants: (("support grid irrigation schemes.") or ("supply crowd information theory."))*.