Gaya APA
Six Thinking Hats. (1990).
England:
Penguin Book.
Gaya Chicago
Six Thinking Hats.
.
England:
Penguin Book,
1990.
Text.
Gaya MLA
Six Thinking Hats.
.
England:
Penguin Book,
1990.
Text.
Gaya Turabian
Six Thinking Hats.
England:
Penguin Book,
1990.
Print.