Perhaps you should try some spelling variations:
hermann book » german book, hermann broch, hermann von
hermann lohr » hermann der, hermann von
heimann book » german book
hall robert » cull robert, gal robert, thiel robert
a robert » 3 robert, dr robert, a robust
robert j » robert e

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: (( hall robert _. ((hermann book) OR (hermann lohr)) ) OR ( a robert j. heimann book ))~.
• Adding a wildcard symbol may retrieve word variants: (( hall robert _. ((hermann book) or (hermann lohr)) ) or ( a robert j. heimann book ))*.