APA Style
The happiness project. (2011).
USA:
Harper Collins Publishers.
Chicago Style
The happiness project.
.
USA:
Harper Collins Publishers,
2011.
Bahasa Inggris.
MLA Style
The happiness project.
.
USA:
Harper Collins Publishers,
2011.
Bahasa Inggris.
Turabian Style
The happiness project.
USA:
Harper Collins Publishers,
2011.
Bahasa Inggris.