(2019). Self-Discipline: Develop Daily Habits to Program Your Mind, Build Mental Toughness, Self-Confidence and WillPower. Independently Published.
Chicago-Zitierstil (17. Ausg.)Self-Discipline: Develop Daily Habits to Program Your Mind, Build Mental Toughness, Self-Confidence and WillPower. USA: Independently Published, 2019.
MLA-Zitierstil (9. Ausg.)Self-Discipline: Develop Daily Habits to Program Your Mind, Build Mental Toughness, Self-Confidence and WillPower. Independently Published, 2019.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.