ACTIVE.. & HOWE, D. d. (1979). Active English for Indonesia: Work book one for Sekolah Menengah Pertama.-- Ed.2. Oxford University Press.

ACTIVE.. and D.H. dkk HOWE. Active English for Indonesia: Work Book One for Sekolah Menengah Pertama.-- Ed.2. Oxford: Oxford University Press, 1979.

ACTIVE.. and D.H. dkk HOWE. Active English for Indonesia: Work Book One for Sekolah Menengah Pertama.-- Ed.2. Oxford University Press, 1979.