Perhaps you should try some spelling variations:
goal robert » gal robert, goal poverty
robert j » robert _, robert e
a robust » _ robust
robust e » robust _, robert e
heitmann » hermann, hartmann
heimann » hermann
book » books, ebook
eebooks » eebookss, eeebooks

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

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