Perhaps you should try some spelling variations:
"support urban irrigation schemes." » "support urban irrigation scheme.", "support urban irrigation systems.", "support murray irrigation schemes.", "support grain irrigation schemes.", "support gray irrigation schemes.", "support carbon irrigation schemes.", "report urban irrigation schemes.", "supply urban irrigation schemes."
"support can information theory." » "support von information theory.", "support von informationen theory.", "support chuan information theory.", "support bank information theory.", "support a information theory."

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

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