Cita APA (7a ed.)

DE BONO, E. (1977). The happiness purpose. Pinguin Books.

Cita Chicago Style (17a ed.)

DE BONO, Edward. The Happiness Purpose. England: Pinguin Books, 1977.

Cita MLA (9a ed.)

DE BONO, Edward. The Happiness Purpose. Pinguin Books, 1977.