APA (7th ed.) Citation

Sinek, S. (2011). Start with why : how great leaders inspire everyone to take action / Simon Sinek: How great leaders inspire everyone to take action ([New] ed.). Portfolio/Penguin.

Chicago Style (17th ed.) Citation

Sinek, Simon. Start with Why : How Great Leaders Inspire Everyone to Take Action / Simon Sinek: How Great Leaders Inspire Everyone to Take Action. [New] ed. New York ; London: Portfolio/Penguin, 2011.

MLA (9th ed.) Citation

Sinek, Simon. Start with Why : How Great Leaders Inspire Everyone to Take Action / Simon Sinek: How Great Leaders Inspire Everyone to Take Action. [New] ed. Portfolio/Penguin, 2011.

Warning: These citations may not always be 100% accurate.