Perhaps you should try some spelling variations:
3 robert » dr robert
a robust » _ robust
robust b » robust _, robust a, robust job
a robot » _ robot
heilmann » heilemann, heimann, heilman
book » books, ebook
eebooks » eebookss, eeebooks
eebookss » eebooksss, eeebookss, ebooks

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((3 robert) or (a robot)) e. heilmann book ) or ( a robust b. heitmann (eebooks OR eebookss) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((3 robert) OR (a robot)) e. heilmann book ) OR ( a robust b. heitmann (eebooks OR eebookss) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((3 robert) or (a robot)) e. heilmann book ) or ( a robust b. heitmann (eebooks OR eebookss) ))".
• Adding a wildcard symbol may retrieve word variants: (( ((3 robert) or (a robot)) e. heilmann book ) or ( a robust b. heitmann (eebooks OR eebookss) ))*.