
- Author: Randy Leffingwell
- Language: English
- Year: 2019

- Author: Randy Leffingwell
- Language: English
- Year: 2021

- Author: Randy Leffingwell
- Language: English
- Year: 2018

- Author: Randy Leffingwell
- Language: English
- Year: 2017

- Author: Joe Oldham, Jim Wangers, Colin Comer, David Newhardt, Randy Leffingwell
- Language: English
- Year: 2013

- Author: Randy Leffingwell
- Language: English
- Year: 2015

- Author: Randy Leffingwell
- Language: English
- Year: 2015

- Author: Randy Leffingwell
- Language: English
- Year: 2013

- Author: Darwin Holmstrom Randy Leffingwell
- Language: English
- Year: 2014

- Author: Randy Leffingwell
- Language: English
- Year: 2010