Perhaps you should try some spelling variations:
a robust » _ robust
a robert » 3 robert, dr robert, a robot
robert j » robert _, robert e
book » books, ebook
ebooks » ebookss, eebooks
redbooks » redbookss, redebooks
redebooks » redebookss, redeebooks
heilmann » heilemann, heimann, heitmann

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

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