Perhaps you should try some spelling variations:
"support gvc integration theories." » "support gvc integration theory.", "support gvc integration through.", "support gvc integration efforts.", "support _ integration theories.", "support eu integration theories.", "support can integration theories.", "support ndc integration theories.", "support agri integration theories."
"support grid integration social." » "support grid international social.", "support trade integration social.", "support _ integration social.", "support data integration social.", "support agri integration social.", "support grant integration social.", "support group integration social."

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("support grid integration social.") OR ("support gvc integration theories."))~.
• Removing quotes may allow a broader search: (( support grid integration social. ) or ( support gvc integration theories. ))~.
• Adding a wildcard symbol may retrieve word variants: (("support grid integration social.") or ("support gvc integration theories."))*.