The Apple Cassette Episode: My Silly Reputation, A Witness To A Wonder, Two Cassettes and 3 Hours of Scrutiny, Ciderpress, A Car With No Gas, Apple Cassette Protection Schemes, 16k, Custom Cards, Vertical Monitor.

The author of Ciderpress gave a great overview of Apple Cassette schemes here: https://fadden.com/apple2/cassette-protect.html

Ciderpress' home page is at https://a2ciderpress.com/

I mention these awesome sites:

http://www.hackzapple.com/INDEX0.HTM

https://www.brutaldeluxe.fr/