It's possible that:
* There is a less known author with that name. You might find more information by searching for him on specific platforms like Goodreads or by checking local library databases.
* The name is slightly different. It's worth double-checking the spelling or searching for variations.
* The author is known by a different name. Perhaps he has a pseudonym.
Could you provide any additional context about William Lemmon? Knowing the genre he writes in, a specific book title, or even a website he's associated with could help narrow down the search.