Perhaps you should try some spelling variations:
"a robert j. heilman book" » "a robert j. german book", "3 robert j. heilman book", "dr robert j. heilman book", "a robust j. heilman book", "a robert _. heilman book"
"a robert e. heilman book" » "a robert e. german book", "3 robert e. heilman book", "dr robert e. heilman book", "a robust e. heilman book", "a robert _. heilman book"
"a robert j. hellman book" » "a robert j. hellman joel", "a robert j. german book", "3 robert j. hellman book", "dr robert j. hellman book", "a robust j. hellman book", "a robert _. hellman 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 j. heilman book") OR ("a robert e. heilman book"))) or ("a robert j. hellman book"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("a robert j. heilman book") OR ("a robert e. heilman book"))) OR ("a robert j. hellman book")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"a robert j. heilman book\") OR (\"a robert e. heilman book\"))) or (\"a robert j. hellman book\"))".
• Removing quotes may allow a broader search: (((( a robert j. heilman book ) OR ( a robert e. heilman book ))) or ( a robert j. hellman book )).
• Adding a wildcard symbol may retrieve word variants: (((("a robert j. heilman book") OR ("a robert e. heilman book"))) or ("a robert j. hellman book"))*.