Perhaps you should try some spelling variations:
gal robert » hall robert
robert e » robert _, robert j
a robust » _ robust
book » books, ebook
eebooks » eebookss, eeebooks
eeebooks » eeebookss, eeeebooks
ebooks » ebookss, eebooks
heilman » heilmann, hellman, helman

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

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