Gaya APA

Peale, N, V. (2009). The Positive Principle Today Berpikir Positif Setiap Hari . Yogyakarta: Ragam Media.

Gaya MLA

Peale, Norman, Vincent. "The Positive Principle Today Berpikir Positif Setiap Hari". Yogyakarta: Ragam Media, 2009. Text.