Perhaps you should try some spelling variations:
"a robert e. hellman book" » "a robert e. hellman joel", "a robert e. german book", "3 robert e. hellman book", "a robust e. hellman book", "a robot e. hellman book", "a robert _. hellman book", "a robert j. hellman book"
"dr robert e. hellman book" » "dr robert e. hellman joel", "dr robert e. german book", "dr robert _. hellman book", "dr robert j. hellman book"
"_ robust e. heilman book" » "_ robust e. german book", "_ robert e. heilman book", "_ robust _. heilman book", "_ robust a. heilman book", "_ robust end. heilman 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 e. hellman book") OR ("dr robert e. hellman book"))) OR ("_ robust e. heilman book"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"a robert e. hellman book\") OR (\"dr robert e. hellman book\"))) OR (\"_ robust e. heilman book\"))".
• Removing quotes may allow a broader search: (((( a robert e. hellman book ) OR ( dr robert e. hellman book ))) OR ( _ robust e. heilman book )).
• Adding a wildcard symbol may retrieve word variants: (((("a robert e. hellman book") OR ("dr robert e. hellman book"))) OR ("_ robust e. heilman book"))*.