Perhaps you should try some spelling variations:
22optical sciences » optical sciences, optical science, nautical sciences
political sciences » political science, political scientists, biological sciences
clinical sciences » clinical science, chemical sciences, technical sciences

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: %((22optical sciences) OR (((political sciences) OR (clinical sciences))))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((22optical sciences) or (((political sciences) OR (clinical sciences))))%22".
• Adding a wildcard symbol may retrieve word variants: %((22optical sciences) or (((political sciences) OR (clinical sciences))))%22*.