Perhaps you should try some spelling variations:
"a robert b. hellman book" » "a robert b. german book", "3 robert b. hellman book", "dr robert b. hellman book", "a robot b. hellman book", "a robert _. hellman book", "a robert e. hellman book", "a robert j. hellman book"
"a robust b. heilmann book" » "_ robust b. heilmann book", "a robust _. heilmann book", "a robust a. heilmann book", "a robust job. heilmann book", "a robust b. heilemann book", "a robust b. heimann book", "a robust b. heitmann book"
"a robert b. hellman joel" » "3 robert b. hellman joel", "dr robert b. hellman joel", "a robot b. hellman joel", "a robert _. hellman joel", "a robert e. hellman joel", "a robert j. hellman joel"

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