(1949). Pursuit of happiness: A primer for modern living. Spero Foundation.
Citazione stile Chigago Style (17a edizione)Pursuit of Happiness: A Primer for Modern Living. New York: Spero Foundation, 1949.
Citatione MLA (8a ed.)Pursuit of Happiness: A Primer for Modern Living. Spero Foundation, 1949.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.