APA (7th ed.) Citation

Kaufman, J. (2013). The first 20 hours: How to learn anything ... fast. Portfolio.

Chicago Style (17th ed.) Citation

Kaufman, Josh. The First 20 Hours: How to Learn Anything ... Fast. New York: Portfolio, 2013.

MLA (8th ed.) Citation

Kaufman, Josh. The First 20 Hours: How to Learn Anything ... Fast. Portfolio, 2013.

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