Perhaps you should try some spelling variations:
international congress » international conference
international theatre » international treaties, international trade, international test
mechanical sciences » mechanical science, technical sciences, clinical sciences
mechanical stresses » mechanical stress, mechanical strength, mechanical structures
international case » international capital, international context

Try widening your search to All Fields.

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 theatre) OR (international case))) OR (international congress)) for ((mechanical sciences) OR (mechanical stresses)), courses AND (lectures" or lecture").
• Removing quotes may allow a broader search: ((((international theatre) or (international case))) or (international congress)) for ((mechanical sciences) or (mechanical stresses)), courses and (lectures or lecture ).
• Adding a wildcard symbol may retrieve word variants: "((((international theatre) or (international case))) or (international congress)) for ((mechanical sciences) or (mechanical stresses)), courses and (lectures" or lecture")*.