Perhaps you should try some spelling variations:
gail robert » gal robert, hall robert, ball robert
robert j » robert _, robert e
_ robust » _ robert
robust e » robust _, robust a, robust end
book » books, ebook
ebookss » ebooksss, eebookss, ebooks
ebooksss » ebookssss, eebooksss, ebookss, ebooks

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( gail robert j. heitmann book ) OR ( _ robust e. hermann (ebookss OR ebooksss) ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( gail robert j. heitmann book ) or ( _ robust e. hermann (ebookss OR ebooksss) ))~".
• Adding a wildcard symbol may retrieve word variants: (( gail robert j. heitmann book ) or ( _ robust e. hermann (ebookss OR ebooksss) ))*.