Basteri, C.G., Clark, B., Gassen, C., & Walker, M. (2014). Marketing dynamics (3rd ed.) [pp. 34-35, 188-189, 102-194, 200-201]. Tinley Park, IL: Goodheart-Willcox.
Boone, L.E., & Kurtz, D.L. (2019). Contemporary marketing (18th ed.) [Lessons 10-1, 10-2, 10-3]. Boston, MA: Cengage Learning, Inc.
Burrow, J.L., & Fowler, A.R. (2016). Marketing (4th ed.) [Lesson 5.1]. Boston, MA: Cengage Learning, Inc.
Lamb, C.W., Hair, Jr., J.H., & McDaniel, C. (2019). MKTG (12th ed.) [Lessons 9-1, 9-2a, 9-2b]. Boston, MA: Cengage Learning, Inc.
Pride, W.M., & Ferrell, O.C. (2019). Foundations of marketing (8th ed.) [Lessons 4-1, 4-3c]. Boston, MA: Cengage Learning, Inc.
Pride, W.M., & Ferrell, O.C. (2020). Marketing (20th ed.) [Lessons 5-1, 5-3c]. Boston, MA: Cengage Learning, Inc.