Perhaps you should try some spelling variations:
medical scientists » biomedical scientists, american scientists, physical scientists
robert walser » robert walker, robert warren, robert winter
robert watson » robert nelson, robert warren

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