Crystal, David, 1941-
The Cambridge encyclopedia of language
Cambridge University Press, 1994
 Buku Referensi
Crystal, David, 1941-
The Cambridge encyclopedia of language
Cambridge University Press, 1991
 Buku Referensi
Crystal, David, 1941-
The Cambridge encyclopedia of language
Cambridge University Press, 1997
 Buku Referensi
Crystal, David, 1941-
Ensiklopedi Bahasa = The Cambridge encyclopedia of language
Nuansa Cendekia, 2015
 Buku Referensi
Cambridge IELTS 7: examination papers from University of Cambridge ESOL examinations: english for speakers of other language
Cambridge University Press, 2009
 Buku Teks