Perhaps you should try some spelling variations:
international congress » international conference
international centre » international theatre, international context, international case
mechanical sciences » chemical sciences, mechanical stresses, clinical sciences
technical sciences » medical sciences, chemical sciences, technical advances
mechanical science » mechanism science, clinical science, mechanical stretch

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 congress)) for ((((mechanical sciences) OR (technical sciences))) OR (mechanical science)), courses AND (lectures" or lecture").
• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((international centre) or (international congress)) for ((((mechanical sciences) OR (technical sciences))) or (mechanical science)), courses and (lectures\" or lecture\")".
• Removing quotes may allow a broader search: ((international centre) or (international congress)) for ((((mechanical sciences) OR (technical sciences))) or (mechanical science)), courses and (lectures or lecture ).
• Adding a wildcard symbol may retrieve word variants: "((international centre) or (international congress)) for ((((mechanical sciences) OR (technical sciences))) or (mechanical science)), courses and (lectures" or lecture")*.