What has the author T H L Parker written?

There is no author by the name of "T H L Parker" that is well-known or has published any notable works. It's possible that:

* The name is misspelled: Could it be a different combination of initials or a slightly different spelling?

* The author is relatively unknown: It's possible this author has written something, but it hasn't gained widespread recognition.

* The author is fictional: It's possible you've encountered this name in a fictional context, like a book or a movie.

Could you provide more context or information about where you came across this name? This might help me identify the author or work you're referring to.