Gaya APA
Rubin, Gretchen. (2018).
The Happiness Project .
United States:
Harper Collins.
Gaya Chicago
Rubin, Gretchen.
The Happiness Project.
United States:
Harper Collins,
2018.
Text.
Gaya MLA
Rubin, Gretchen.
The Happiness Project.
United States:
Harper Collins,
2018.
Text.
Gaya Turabian
Rubin, Gretchen.
The Happiness Project.
United States:
Harper Collins,
2018.
Print.