Perhaps you should try some spelling variations:
heimann book » german book
heilman book » german book
a robert » 3 robert, dr robert, a robot
robert e » robert _, robert j
a robust » _ robust
robust e » robust _, robust a, robust end
heilmann » heilemann, heitmann, heinemann

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

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