Perhaps you should try some spelling variations:
gal robert » hall robert
robert j » robert _
a robert » 3 robert, dr robert, a robust
robert e » robert _
book » books, ebook
ebooks » ebookss, eebooks
eebooks » eebookss, eeebooks
eeebooks » eeebookss, eeeebooks, redbooks, texbooks
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 j. heitmann book ) or ( a robert e. heilman (ebooks or (eebooks OR eeebooks)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( gal robert j. heitmann book ) OR ( a robert e. heilman (ebooks OR (eebooks OR eeebooks)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( gal robert j. heitmann book ) or ( a robert e. heilman (ebooks or (eebooks OR eeebooks)) ))".
• Adding a wildcard symbol may retrieve word variants: (( gal robert j. heitmann book ) or ( a robert e. heilman (ebooks or (eebooks OR eeebooks)) ))*.