APA
Thorpe D. A., . (1993). Study Guide for Speaking Professionally Module-6, Lesson 30-36. USA: Lingua Marketing International.
Chicago
Thorpe Dale A, . 1993. Study Guide for Speaking Professionally Module-6, Lesson 30-36. USA: Lingua Marketing International.
Harvard
Thorpe D. A., . (1993). Study Guide for Speaking Professionally Module-6, Lesson 30-36. USA: Lingua Marketing International.
MLA
Thorpe Dale A, . Study Guide for Speaking Professionally Module-6, Lesson 30-36. USA: Lingua Marketing International. 1993.