Gaya APA
Roberts, Kenneth. (1953).
Northwest Passage .
London:
Fontana Books.
Gaya Chicago
Roberts, Kenneth.
Northwest Passage.
London:
Fontana Books,
1953.
Text.
Gaya MLA
Roberts, Kenneth.
Northwest Passage.
London:
Fontana Books,
1953.
Text.
Gaya Turabian
Roberts, Kenneth.
Northwest Passage.
London:
Fontana Books,
1953.
Print.