The Yetzer is Necessary: A Star Trek Episode
A Special Drug Can Amplify the Yetzer: Dr. Jekyll and Captain America
The Yetzer Hara is on the Side of Good: Willy Wonka and the Zohar
The Psychology of the Yetzer Hara: The Screwtape Letters
Appendix:
What Does Charlie Do to Deserve Winning the Chocolate Factory?