(1990). Linguaphone Intermediate English Course Futher Practice Exercises. Linguaphone Institute Limited.
Chicago-viite (17. p.)Linguaphone Intermediate English Course Futher Practice Exercises. Linguaphone Institute Limited, 1990.
MLA-viite (8. p.)Linguaphone Intermediate English Course Futher Practice Exercises. Linguaphone Institute Limited, 1990.
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