Perhaps you should try some spelling variations:
international convention » international cooperation, national convention, international conference
international congress » international conference
international theatre » international treaties, international trade, international test
international context » international conference
international centre » international case, international capital
mechanical sciences » mechanical science, technical sciences, mechanical stresses
lectures » lecture

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: ((((((international centre) OR (international convention))) OR (international theatre))) OR (((international context) OR (international congress)))) for mechanical sciences, courses AND lectures.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((international centre) OR (international convention))) or (international theatre))) or (((international context) or (international congress)))) for mechanical sciences, courses and lectures".
• Adding a wildcard symbol may retrieve word variants: ((((((international centre) OR (international convention))) or (international theatre))) or (((international context) or (international congress)))) for mechanical sciences, courses and lectures*.