* The name is misspelled. Double-check the spelling.
* The author uses a pen name. Try searching under different names or looking up any other details you know about the author (like their genre or country of origin).
* The author is relatively unknown or unpublished.
To help me find information about the author, could you please provide more context? For example:
* What kind of books do they write? (Genre, topic, etc.)
* Do you know anything else about them? (Nationality, era they lived in, etc.)
* Where did you encounter this name? (Book cover, article, website, etc.)
With more information, I can try to help you find more about "John Douglas Adam."