Gaya APA
Rubin, Gretchen. (2016).
The Happiness Project .
Surabaya:
Menuju Insan Cemerlang.
Gaya Chicago
Rubin, Gretchen.
The Happiness Project.
Surabaya:
Menuju Insan Cemerlang,
2016.
Text.
Gaya MLA
Rubin, Gretchen.
The Happiness Project.
Surabaya:
Menuju Insan Cemerlang,
2016.
Text.
Gaya Turabian
Rubin, Gretchen.
The Happiness Project.
Surabaya:
Menuju Insan Cemerlang,
2016.
Print.