Carl Koch. (1982). Communication skills for college students. National Book Store.
Chicago-referens (17:e uppl.)Carl Koch. Communication Skills for College Students. Manila: National Book Store, 1982.
MLA-referens (9:e uppl.)Carl Koch. Communication Skills for College Students. National Book Store, 1982.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.