Perhaps you should try some spelling variations:
heilmann books » heilmann doris
heimann book » german book
gael robert » gal robert, hall robert, biel robert
ball robert » hall robert, bill robert, ballon robert
a robert » 3 robert, dr robert, a robust
robert a » robert _, robert e, robert j

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((gael robert) OR (ball robert)) j. heimann book ) or ( a robert a. heilmann books ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((gael robert) OR (ball robert)) j. heimann book ) OR ( a robert a. heilmann books )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((gael robert) OR (ball robert)) j. heimann book ) or ( a robert a. heilmann books ))".
• Adding a wildcard symbol may retrieve word variants: (( ((gael robert) OR (ball robert)) j. heimann book ) or ( a robert a. heilmann books ))*.