Ries, A., & Trout, J. (1989). Bottom-up marketing. McGraw-Hill.
Cita Chicago (17th ed.)Ries, Al, i Jack Trout. Bottom-up Marketing. New York: McGraw-Hill, 1989.
Cita MLA (9th ed.)Ries, Al, i Jack Trout. Bottom-up Marketing. McGraw-Hill, 1989.
Atenció: Aquestes cites poden no estar 100% correctes.