Perhaps you should try some spelling variations:
heimann book » german book
heilman book » german book
a robust » _ robust
robust e » robust _, robust end, robust l1
robust a » robust _, robust cat, robust lca
a robot » _ robot
robot j » robot _, robot 1, robot 5

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

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