Perhaps you should try some spelling variations:
"support crop irrigation schemes." » "support crop irrigation scheme.", "support crop irrigation systems.", "support drip irrigation schemes.", "support scale irrigation schemes.", "support canal irrigation schemes.", "support crops irrigation schemes.", "support group irrigation schemes.", "support cross irrigation schemes."
"supply grid information theory." » "supply rapid information theory.", "supply child information theory.", "supply road information theory.", "supply crowd information theory.", "support grid 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 crop irrigation schemes.") OR ("supply grid information theory."))~.
• Removing quotes may allow a broader search: (( support crop irrigation schemes. ) or ( supply grid information theory. ))~.
• Adding a wildcard symbol may retrieve word variants: (("support crop irrigation schemes.") or ("supply grid information theory."))*.