Perhaps you should try some spelling variations:
poverty e » poverty _, poverty a, poverty g8
poverty m » poverty _, poverty a, poverty map
a robust » _ robust
robust e » robust _, robert e
heitmann » heimann, heinemann, hermann
book » ebook
books » ebooks
hellman » helpman

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( local ((poverty e) OR (poverty m)). heitmann book ) or ( a robust e. hellman books ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( local ((poverty e) OR (poverty m)). heitmann book ) OR ( a robust e. hellman books ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( local ((poverty e) OR (poverty m)). heitmann book ) or ( a robust e. hellman books ))*".