Lewis Michael. (2017). Undoing Project: Friendship that Changed the World. Penguin Books.
Chicago-referens (17:e uppl.)Lewis Michael. Undoing Project: Friendship That Changed the World. Penguin Books, 2017.
MLA-referens (9:e uppl.)Lewis Michael. Undoing Project: Friendship That Changed the World. Penguin Books, 2017.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.