Vom Zeitmanagement zur Zeitintelligenz
2014
PoweReading®
2009
Pacific Crest Trials: A Psychological and Emotional Guide to Successfully Thru-Hiking the Pacific Crest Trail
2017
Die Löwen-Liga: Der Weg in die Selbstständigkeit
2015
Die Löwen-Liga
2013
Appalachian Trials - A Psychological and Emotional Guide to Successfully Thru-Hiking the Appalachian Trail
2012