* The name is misspelled: There might be a similar-sounding name that's the correct one. Can you double-check the spelling?
* The author is relatively unknown: Many authors write books that don't become widely known. It's possible that this author has published works that haven't gained mainstream attention.
* You're thinking of a different William McNamara: There are several people with this name, so you might be thinking of someone else entirely. For example, there's an actor named William McNamara.
To help me find the right author, please provide me with more information. For example:
* What kind of books do you think they wrote? (Genre, subject matter, etc.)
* Do you remember any titles or specific details about their books?
* Is there any other information you have about them, like their nationality or a time period they wrote in?
With more information, I can try to locate the correct William McNamara and find their published works.