Perhaps you should try some spelling variations:
"supply trade interaction series." » "supply trade interactions series.", "supply trade interaction studies.", "supply trade interaction terms.", "supply trade integration series.", "supply face interaction series.", "supply time interaction series.", "supply case interaction series."
"supply border integration series." » "supply der integration series.", "supply merger integration series.", "supply border migration series.", "supply border integration services.", "supply border integration server.", "supply border integration theories.", "supply order integration series.", "supply under integration series."

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

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