Koi Organisation International (KOI) put together a review of more than 2 dozen books, videos etc. Better still, they had THREE reviewers weighing in. This provided valuable insights from 'different' points of view. All good books and resources. Another “nice value” that's added to Koi Organisation International. 

Here's a link to the reference: 

If the link doesn't work, I'm uploading the list as a PDF and let me know. 

Doc Johnson