Perhaps you should try some spelling variations:
"supply data integration theory." » "supply data integration through.", "supply data information theory.", "supply data integration report.", "supply trade integration theory.", "supply _ integration theory.", "supply data integrity theory.", "supply water integration theory."
"supply crop irrigation system." » "supply crop irrigation systems.", "supply crop irrigation water.", "supply crop irrigation scheme.", "supply drip irrigation system.", "supply scale irrigation system.", "supply canal irrigation system.", "supply crowd irrigation system.", "supply curve irrigation system."

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

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