Perhaps you should try some spelling variations:
international convention » international cooperation, international context, international communication
convention janet » convention james, convention aine, convention area
janet decision » manet decision, market decision, agent decision
theory several » theory general
theory level » every level, theory local, theory lewis

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

• Performing a fuzzy search may retrieve terms with similar spellings: international convention janet decision ((theory level) OR (theory several))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "international convention janet decision ((theory level) OR (theory several))".
• Adding a wildcard symbol may retrieve word variants: international convention janet decision ((theory level) OR (theory several))*.