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