Perhaps you should try some spelling variations:
wrobel robert » ebel robert, fimbel robert
heilmann » heinemann, hermann, heymann
hellman » helpman
heimann » hermann, heinemann
heitmannn » heinemannn, hermannn, hartmannn
heitmann » heinemann, hermann, hartmann
book » books, ebook

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

• Performing a fuzzy search may retrieve terms with similar spellings: wrobel robert _. ((heilmann OR hellman) OR (heimann OR (heitmannn OR heitmann))) book~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wrobel robert _. ((heilmann OR hellman) OR (heimann OR (heitmannn OR heitmann))) book".
• Adding a wildcard symbol may retrieve word variants: wrobel robert _. ((heilmann OR hellman) OR (heimann OR (heitmannn OR heitmann))) book*.