Gaya APA
Boyd, R., Silk, J, B. (2011).
How Humans Evolved (Sixth Edition) (Ed 6 Cet 1).
New York:
W.W Norton & Company.
Gaya MLA
Boyd, Robert., Silk, Joan, B..
"How Humans Evolved (Sixth Edition)".
Ed 6 Cet 1
New York:
W.W Norton & Company,
2011.
Text.