THe New Lexicon Webster's Dictionary of the English Language Volume 2 (Encyclopedic Edition)
Danbury : Lexicon Publications, Inc., 2004,
 Buku Referensi
Crawley, Angela, author
Oxford Elementary Learner's English - Chinese Dictionary (Second Edition)
Oxford University Press, 1994
 Buku Referensi
Burke, Claire
Kenntnisse : an advanced German course student's book / Claire Burke
New York Routledge, 1999
 Buku Teks
Rozakis, Laurie
Advanced placement examination in english : composition and literature / Laurie Rozakis
ARCO, 1990
 Buku Teks
Bradford, Barbara
Intonation in context : intonation practice for upper-intermediate and advanced learners of English
Cambridge University Press, 1988
 Buku Teks