- Passkey EA Review Workbook: Six Complete Enrolled Agent Practice Exams, 2015-2016 Edition
- Passkey Learning Systems EA Review Workbook: Six Complete IRS Enrolled Agent Practice Exams 2018-2019 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 2015-2016 Edition
- Passkey EA Review Workbook: Six Complete Enrolled Agent Practice Exams, 2017-2018 Edition