(1990). Linguaphone Intermediate English Course Futher Practice Exercises. Linguaphone Institute Limited.
Chicago-referens (17:e uppl.)Linguaphone Intermediate English Course Futher Practice Exercises. Linguaphone Institute Limited, 1990.
MLA-referens (8:e uppl.)Linguaphone Intermediate English Course Futher Practice Exercises. Linguaphone Institute Limited, 1990.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.