editor-publisher, Hack-cho Mah
Asia PR Center, 1975
Buku Teks SO
Tomlinson, Jim
Methuen, 1981
Buku Teks SO
Wells, S.J.
Cambridge University Press, 1964
Buku Teks
Endres, Elisabeth
Frankfurt Fischer Taschenbuch verlag GmbH 1975
Buku Teks
edited by Tony Buxton, Paul Chapman and Paul Temple
Routledge , 1994
Buku Teks