Perhaps you should try some spelling variations:
gail robert » gal robert, hall robert, ball robert
robert e » robert _, robert j
a robert » 3 robert, dr robert, a robot
a robust » _ robust
book » books
ebook » ebooks
eebookss » eebooksss, ebooks
heimann » heinemann

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

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