Perhaps you should try some spelling variations:
american societies » american society, american science, american association
american cities » african cities, american countries, american colonies
robert walt » robert watt, robert wait, robert walter

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 walt) OR (robert white)) (((american societies) OR (american cities))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((robert walt) or (robert white)) (((american societies) OR (american cities)))".
• Adding a wildcard symbol may retrieve word variants: ((robert walt) or (robert white)) (((american societies) OR (american cities)))*.