APA (7th ed.) Citation

ALLEN. (2003). Getting thing done: The art of stress-free productivity. Penguin Books.

Chicago Style (17th ed.) Citation

ALLEN. Getting Thing Done: The Art of Stress-free Productivity. New York: Penguin Books, 2003.

MLA (9th ed.) Citation

ALLEN. Getting Thing Done: The Art of Stress-free Productivity. Penguin Books, 2003.

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