Perhaps you should try some spelling variations:
engineering discoveries » engineering discovering, engineering discovery, engineering fisheries
mechanical engineering » electrical engineering
engineering theories » engineering theory, engineering theses, engineering textiles

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: (( mechanical engineering theories ) OR ( mechanical engineering discoveries )).
• Adding a wildcard symbol may retrieve word variants: (( mechanical engineering theories ) or ( mechanical engineering discoveries ))*.