APA Style
Porter, Michael, E.. (1980).
Competitive strategy .
New York:
THE FREE PRESS.
Chicago Style
Porter, Michael, E..
Competitive strategy.
New York:
THE FREE PRESS,
1980.
Text.
MLA Style
Porter, Michael, E..
Competitive strategy.
New York:
THE FREE PRESS,
1980.
Text.
Turabian Style
Porter, Michael, E..
Competitive strategy.
New York:
THE FREE PRESS,
1980.
Print.