Kirkpatrick, D. L. (2007). Implementing the four levels: A practical guide for effective evaluation of training programs. Berrett-Koehler Publishers.
Chicago-Zitierstil (17. Ausg.)Kirkpatrick, Donald L. Implementing the Four Levels: A Practical Guide for Effective Evaluation of Training Programs. San Francisco: Berrett-Koehler Publishers, 2007.
MLA-Zitierstil (9. Ausg.)Kirkpatrick, Donald L. Implementing the Four Levels: A Practical Guide for Effective Evaluation of Training Programs. Berrett-Koehler Publishers, 2007.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.