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-
The Cambridge encyclopedia of language
Cambridge University Press, 1994
 Buku Referensi
Encyclopedic dictionary of applied linguistics : a handbook for language teaching
edited by Keith and Helen Johnson
Blackwell, 1999
 Buku Referensi
Crystal, David, 1941-
A dictionary of linguistics and phonetics
Blackwell Publishers, 1998
 Buku Referensi