Perhaps you should try some spelling variations:
"support group irrigation schemes." » "support group irrigation scheme.", "support group irrigation systems.", "support crop irrigation schemes.", "support drip irrigation schemes.", "support from irrigation schemes.", "support grant irrigation schemes."
"supply child information theory." » "supply chief information theory.", "supply card information theory.", "supply field information theory.", "supply chains information theory.", "supply chain information theory.", "supply crowd 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 group irrigation schemes.") OR ("supply child information theory."))~.
• Removing quotes may allow a broader search: (( support group irrigation schemes. ) or ( supply child information theory. ))~.
• Adding a wildcard symbol may retrieve word variants: (("support group irrigation schemes.") or ("supply child information theory."))*.