Perhaps you should try some spelling variations:
marill robert » marshall robert, carroll robert, hall robert
german books » german book, german food
ball robert » hall robert, bill robert, ballon robert
gal robert » hall robert
heilmann » heilemann, heimann, heitmann
book » ebook
books » ebooks

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((marill robert) or (ball robert)) e. heilmann book ) or ( gal robert _. german books ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((marill robert) OR (ball robert)) e. heilmann book ) OR ( gal robert _. german books )).
• Adding a wildcard symbol may retrieve word variants: (( ((marill robert) or (ball robert)) e. heilmann book ) or ( gal robert _. german books ))*.