Perhaps you should try some spelling variations:
"supply grid integration theories." » "supply grid integration theorems.", "supply grid integrationstheorie 2.", "supply grid integration theory.", "supply crowd integration theories.", "supply great integration theories.", "support grid integration theories."
"supply grid importing countries." » "supply grid exporting countries.", "supply grid importing country.", "supply oil importing countries.", "supply food importing countries.", "supply gas importing countries.", "supply crowd importing countries.", "supply great importing countries.", "support grid importing countries."

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

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