APA (7th ed.) Citation

Roman, E., & Hornstein. (2004). Opt-in marketing: Increase sales exponentially with consensual marketing. McGraw-Hill.

Chicago Style (17th ed.) Citation

Roman, Ernan, and Hornstein. Opt-in Marketing: Increase Sales Exponentially with Consensual Marketing. New York: McGraw-Hill, 2004.

MLA (8th ed.) Citation

Roman, Ernan, and Hornstein. Opt-in Marketing: Increase Sales Exponentially with Consensual Marketing. McGraw-Hill, 2004.