Citazione Stile APA (7a Edizione)

Fredrickson, B. (2009). Positivity (First edition.). Three Rivers Press.

Citazione stile Chigago Style (17a edizione)

Fredrickson, Barbara. Positivity. First edition. New York: Three Rivers Press, 2009.

Citatione MLA (9a ed.)

Fredrickson, Barbara. Positivity. First edition. Three Rivers Press, 2009.