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 crop irrigation system.") or ("supply data integration theory."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply crop irrigation system.") OR ("supply data integration theory.")).
• Removing quotes may allow a broader search: (( supply crop irrigation system. ) or ( supply data integration theory. )).
• Adding a wildcard symbol may retrieve word variants: (("supply crop irrigation system.") or ("supply data integration theory."))*.