APA
Thorpe D. A., . (1993). Study Guide for Speaking Professionally Module 5 Lesson 25-30. USA: Lingua Marketing Internationals.
Chicago
Thorpe Dale A, . 1993. Study Guide for Speaking Professionally Module 5 Lesson 25-30. USA: Lingua Marketing Internationals.
Harvard
Thorpe D. A., . (1993). Study Guide for Speaking Professionally Module 5 Lesson 25-30. USA: Lingua Marketing Internationals.
MLA
Thorpe Dale A, . Study Guide for Speaking Professionally Module 5 Lesson 25-30. USA: Lingua Marketing Internationals. 1993.