This course does not require you to purchase a textbook. All of the learning materials you need are provided in the course. We do rely heavily on the following Open Textbook:
Principles of Marketing Version 3
John F. Tanner, Jr.and Mary Anne Raymond
You can access the free and open copy at: https://biz.libretexts.org/Bookshelves/Marketing/Principles_of_Marketing_(LibreTexts)
Links to specific sections and chapters are also included within each module in the course.