New York : Holt, Rinehart and Winston, 1995,
Buku Teks
Hartmann, Reinhard R.K., author
Tubingen [Gunter Narr verlag] 1973
Buku Teks
Klatt, Edmund
Berlin Langenscheidt KG. Verlag buchhandlung 1961
Buku Referensi
London, London Longmans
Buku Referensi
London; Cassell LTD., 1978
Buku Referensi