Gaya APA
Stumbling on Happiness. (2006).
New York:
.
Gaya Chicago
Stumbling on Happiness.
Cetakan I.
New York:
,
2006.
Text.
Gaya MLA
Stumbling on Happiness.
Cetakan I.
New York:
,
2006.
Text.
Gaya Turabian
Stumbling on Happiness.
New York:
,
2006.
Print.