Perhaps you should try some spelling variations:
"supply digital transformation theory." » "supply digital transformative theory.", "supply digital transformation through.", "supply digital transformation history.", "survey digital transformation theory."
"supply can integration theory." » "supply can integration through.", "supply can information theory.", "supply can innovation theory.", "supply chain integration theory.", "supply von integration theory.", "supply urban integration theory.", "supply case integration theory.", "supply chai integration theory."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("supply can integration theory.") or ("supply digital transformation theory."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply can integration theory.") OR ("supply digital transformation theory.")).
• Removing quotes may allow a broader search: (( supply can integration theory. ) or ( supply digital transformation theory. )).
• Adding a wildcard symbol may retrieve word variants: (("supply can integration theory.") or ("supply digital transformation theory."))*.