Perhaps you should try some spelling variations:
"a robust e. heilman book" » "a robust e. german book", "_ robust e. heilman book", "a robust a. heilman book", "a robust end. heilman book", "a robust l1. heilman book"
"a robust _. heilman book" » "a robust _. german book", "_ robust _. heilman book"
"a robert e. heitmann book" » "3 robert e. heitmann book", "dr robert e. heitmann book", "a robot e. heitmann book", "a robert _. heitmann book", "a robert j. heitmann book"

Try widening your search to All Fields.

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