(2019). Self-Discipline: Develop Daily Habits to Program Your Mind, Build Mental Toughness, Self-Confidence and WillPower. Independently Published.
Chicago-referens (17:e uppl.)Self-Discipline: Develop Daily Habits to Program Your Mind, Build Mental Toughness, Self-Confidence and WillPower. USA: Independently Published, 2019.
MLA-referens (9:e uppl.)Self-Discipline: Develop Daily Habits to Program Your Mind, Build Mental Toughness, Self-Confidence and WillPower. Independently Published, 2019.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.