Perhaps you should try some spelling variations:
poverty map » poverty gap
poverty a » poverty _, poverty gap, poverty data
a robust » _ robust
heitmannn » heitmann, heimann, heilmann
book » books, ebook
eebookss » eebooksss, eeebookss, ebooks
heilman » heilmann, hellman, heitmann

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 a) OR (poverty map)). heitmannn book ) or ( a robust _. heilman eebookss ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( local ((poverty a) OR (poverty map)). heitmannn book ) OR ( a robust _. heilman eebookss ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( local ((poverty a) OR (poverty map)). heitmannn book ) or ( a robust _. heilman eebookss ))*".