APA Style

Kotler, Philip, Armstrong, Gary. (1990). Principles of Marketing / Philip Kotler and Gary Armstrong (6th ed.). New Jersey: Prentice Hall.

Chicago Style

Kotler, Philip, Armstrong, Gary. Principles of Marketing / Philip Kotler and Gary Armstrong. 6th ed. New Jersey: Prentice Hall, 1990. Text.

MLA Style

Kotler, Philip, Armstrong, Gary. Principles of Marketing / Philip Kotler and Gary Armstrong. 6th ed. New Jersey: Prentice Hall, 1990. Text.

Turabian Style

Kotler, Philip, Armstrong, Gary. Principles of Marketing / Philip Kotler and Gary Armstrong. 6th ed. New Jersey: Prentice Hall, 1990. Print.