Perhaps you should try some spelling variations:
"support trade integration theories." » "support trade integration theorems.", "support trade integrationstheorie 2.", "support trade integration theory.", "support trainer integration theories.", "export trade integration theories.", "import trade integration theories."
"support grid integration schemes." » "support grid integration schengen.", "support grid irrigation schemes.", "support grid integration regimes.", "support agri integration schemes.", "support grant integration schemes.", "support group integration schemes."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("support grid integration schemes.") OR ("support trade integration theories."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"support grid integration schemes.\") OR (\"support trade integration theories.\"))*".
• Removing quotes may allow a broader search: (( support grid integration schemes. ) OR ( support trade integration theories. ))*.