Perhaps you should try some spelling variations:
"supply can integration theories." » "supply can integration theorems.", "supply can integrationstheorie 2.", "supply can integration theory.", "supply chain integration theories.", "supply von integration theories.", "supply urban integration theories.", "supply case integration theories.", "supply chai integration theories."
"supply china immigration policy." » "supply china migration policy.", "supply chinese immigration policy.", "supply china integration policy.", "supply chains immigration policy.", "supply chain immigration policy."

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"supply china immigration policy.\") OR (\"supply can integration theories.\"))~".
• Removing quotes may allow a broader search: (( supply china immigration policy. ) OR ( supply can integration theories. ))~.
• Adding a wildcard symbol may retrieve word variants: (("supply china immigration policy.") OR ("supply can integration theories."))*.