Perhaps you should try some spelling variations:
"support can irrigation schemes." » "support can irrigation scheme.", "support can irrigation systems.", "support canal irrigation schemes.", "support change irrigation schemes.", "support scale irrigation schemes.", "support bank irrigation schemes.", "support a irrigation schemes.", "support tax irrigation schemes."
"support debt information theory." » "support student information theory.", "support credit information theory.", "support health information theory.", "support deep information theory.", "support data information theory.", "support does 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 can irrigation schemes.") or ("support debt information theory."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("support can irrigation schemes.") OR ("support debt information theory.")).
• Removing quotes may allow a broader search: (( support can irrigation schemes. ) or ( support debt information theory. )).
• Adding a wildcard symbol may retrieve word variants: (("support can irrigation schemes.") or ("support debt information theory."))*.