Gaya APA

Hartman, S, S, ;, D, B, V. (2011). How Great Leaders Inspire Everyone to Take Action (Paperback edition with a new preface and new after). New York: Portfolio / Penguin.

Gaya MLA

Hartman, Simon, Sinek, ;, Designed, By, Victoria. "How Great Leaders Inspire Everyone to Take Action". Paperback edition with a new preface and new after New York: Portfolio / Penguin, 2011. Text.