Perhaps you should try some spelling variations:
political scientist » political scientists, political sciences, clinical scientist
social scientists » social sciences
mark webber » mark weber, mr webber, mark weiser

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: mark webber (((political scientist) OR (social scientists))).
• Adding a wildcard symbol may retrieve word variants: mark webber (((political scientist) or (social scientists)))*.