Perhaps you should try some spelling variations:
american scientist » american scientists, american scientific, american science
robert walsh » robert walser, robert walt, robert walsers
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 walsh) OR (robert welch)) (american scientist).
• Adding a wildcard symbol may retrieve word variants: ((robert walsh) or (robert welch)) (american scientist)*.