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