Perhaps you should try some spelling variations:
physical scientists » political scientists, physical sciences, physical societies
medical scientists » biomedical scientists, american scientists, medical sciences
robert welch » robert weech, robert wrench, robert wells

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: robert welch (((medical scientists) OR (physical scientists))).
• Adding a wildcard symbol may retrieve word variants: robert welch (((medical scientists) or (physical scientists)))*.