Perhaps you should try some spelling variations:
international efforts » international airports, international energy, international airport
integration theories » integration theorems, integrationstheorie 2, integration theory
chain international » chains international, main international, can international
supply grid » supply crowd, supply great, support grid

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 chain international efforts. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply grid integration theories. ) OR ( supply chain international efforts. )).
• Adding a wildcard symbol may retrieve word variants: (( supply grid integration theories. ) or ( supply chain international efforts. ))*.