What has the author J K Hyer written?

There is no known author named J K Hyer. It's possible there's a typo or you're thinking of a different author.

Could you please double-check the name or provide more context? For example:

* Is there a specific book or genre you're looking for?

* Do you have any other information about the author, such as their nationality or the time period they wrote in?

With more details, I might be able to help you find the author you're looking for.