* The name is misspelled: Perhaps there's a slight variation in the spelling of his name. Could you double-check the spelling?
* The author is less known: He might be a lesser-known author or published under a different name.
* He's not an author: It's possible that Karl J. Heilman is not an author at all.
To help me find more information, could you provide any additional context? For example:
* What kind of books do you think he wrote? (Fiction, non-fiction, specific genre?)
* Do you have any other information about him? (Time period, location, etc.)
With more information, I might be able to find more details about his writings.