- PassKey Learning Systems EA Review Part 1 Individuals; Enrolled Agent Study Guide: May 1, 2020-February 28, 2021 Testing Cycle
- Passkey EA Review, Part 2: Businesses, IRS Enrolled Agent Exam Study Guide 2014-2015 Edition
- Passkey EA Review Complete: Individuals, Businesses, and Representation: IRS Enrolled Agent Exam Study Guide 2014-2015 Edition
- Passkey Learning Systems EA Review, Part 2 Businesses; Enrolled Agent Study Guide: July 1, 2019-February 29, 2020 Testing Cycle
- Passkey EA Review, Part 2: Businesses, IRS Enrolled Agent Exam Study Guide 2016-2017 Edition