Perhaps you should try some spelling variations:
"a robust e. hellman book" » "a robust e. hellman joel", "_ robust e. hellman book", "a robust _. hellman book", "a robert e. hellman book"
"a robert _. heilman book" » "gal robert _. heilman book", "a robert _. heilmann book", "a robert _. heitmann book"
"a robert j. heilman book" » "gal robert j. heilman book", "a robert e. heilman book", "a robert j. heilmann book", "a robert j. heitmann book"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("a robert _. heilman book") or ("a robert j. heilman book"))) or ("a robust e. hellman book"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("a robert _. heilman book") OR ("a robert j. heilman book"))) OR ("a robust e. hellman book")).
• Removing quotes may allow a broader search: (((( a robert _. heilman book ) or ( a robert j. heilman book ))) or ( a robust e. hellman book )).
• Adding a wildcard symbol may retrieve word variants: (((("a robert _. heilman book") or ("a robert j. heilman book"))) or ("a robust e. hellman book"))*.