Gaya APA
Douglas, E, J., Callan, S. (1992).
Managerial economics : analysis and strategy (4e).
New Jersey:
Prentice Hall International.
Gaya MLA
Douglas, Evan, J., Callan, Scott.
"Managerial economics : analysis and strategy".
4e
New Jersey:
Prentice Hall International,
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Buku.