Hill, C. y Jones, G. (2011). Administración Estratégica: un enfoque integral (9ª ed.). México: Cengage Learning.
ISBN: 978-607-481-322-7

Porter, M. (2008). The Five Competitive Forces That Shape Strategy. Harvard Business Review.
Recuperado el 30 de abril de 2014  de http://hbr.org/2008/01/the-five-competitive-forces-that-shape-strategy/ar/1