It's possible:
* The name is misspelled. Are you sure you have the correct spelling? Try searching for similar variations.
* The author is relatively unknown. There may be a lesser-known author with that name whose works haven't gained widespread recognition.
* The author uses a pen name. Perhaps William Muskerry is a pseudonym.
Could you please provide any further details you might have about this author, such as their genre, era, or any specific works you've heard of? This would help me find the information you're looking for.