Perhaps you should try some spelling variations:
"support agri irrigation schemes." » "support agri irrigation scheme.", "support agri irrigation systems.", "support africa irrigation schemes.", "support grain irrigation schemes.", "support syria irrigation schemes.", "support grid irrigation schemes.", "support aging irrigation schemes.", "support a irrigation schemes."
"support policy information theory." » "support policy formation theory.", "support public information theory.", "support policy innovation theory.", "support policies information theory.", "import policy 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 agri irrigation schemes.") OR ("support policy information theory."))~.
• Removing quotes may allow a broader search: (( support agri irrigation schemes. ) or ( support policy information theory. ))~.
• Adding a wildcard symbol may retrieve word variants: (("support agri irrigation schemes.") or ("support policy information theory."))*.