Schuller, R. (1985). The be happy attitudes: Eight postive attitudes that can transform your life. Word books.
Citazione stile Chigago Style (17a edizione)Schuller, Robert. The Be Happy Attitudes: Eight Postive Attitudes That Can Transform Your Life. Texas: Word books, 1985.
Citatione MLA (9a ed.)Schuller, Robert. The Be Happy Attitudes: Eight Postive Attitudes That Can Transform Your Life. Word books, 1985.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.