Perhaps you should try some spelling variations:
mechanical efficiency » technical efficiency
international context » international congress, international conference
international centre » international theatre, international case, international capital
mechanical science » mechanism science, mechanical stretch, mechanical impedance
clinical science » political science, clinical evidence, ecological science
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 for mechanical science, courses AND lectures ) OR ( international centre for mechanical efficiency, courses AND lectures ))) OR ( international context for clinical science, courses AND lectures )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( international centre for mechanical science, courses and lectures ) OR ( international centre for mechanical efficiency, courses and lectures ))) or ( international context for clinical science, courses and lectures ))".
• Adding a wildcard symbol may retrieve word variants: (((( international centre for mechanical science, courses and lectures ) OR ( international centre for mechanical efficiency, courses and lectures ))) or ( international context for clinical science, courses and lectures ))*.