Perhaps you should try some spelling variations:
physical scientists » political scientists, physical sciences, physical societies
medical scientists » biomedical scientists, american scientists, medical sciences
robert walsh » robert walser, robert walt, robert walsers
robert welch » robert weech, robert wrench, robert wells
robert watt » robert watson, robert white

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))) OR (robert watt)) (((medical scientists) OR (physical scientists))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((robert walsh) or (robert welch))) or (robert watt)) (((medical scientists) OR (physical scientists)))".
• Adding a wildcard symbol may retrieve word variants: ((((robert walsh) or (robert welch))) or (robert watt)) (((medical scientists) OR (physical scientists)))*.