Gaya APA

Rubin, Gretchen. (2019). The Happiness Project . USA: Harper.

Gaya Chicago

Rubin, Gretchen. The Happiness Project. USA: Harper, 2019. Text.

Gaya MLA

Rubin, Gretchen. The Happiness Project. USA: Harper, 2019. Text.

Gaya Turabian

Rubin, Gretchen. The Happiness Project. USA: Harper, 2019. Print.