Perhaps you should try some spelling variations:
heilman book » german book
goal robert » gal robert, deal robert, fogel robert
robert e » robert _, robert j
a robust » _ robust
robust e » robust _, robust a, robust end
heilmann » heilemann, heimann, heitmann
eeebooks » redbooks, ebooks, texbooks

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: (( goal robert e. heilman book ) OR ( a robust e. heilmann (eebooks OR eeebooks) ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( goal robert e. heilman book ) or ( a robust e. heilmann (eebooks OR eeebooks) ))~".
• Adding a wildcard symbol may retrieve word variants: (( goal robert e. heilman book ) or ( a robust e. heilmann (eebooks OR eeebooks) ))*.