Andrew, Nancy Learmonth, compiled
Frederick Warne & Co , 1973
Buku Referensi
Crystal, David, 1941-
Cambridge University Press, 1994
Buku Referensi
Crystal, David, 1941-
Cambridge University Press, 1995
Buku Referensi
edited by Adrian Friday, David S. Ingram
Cambridge University Press, 1985
Buku Referensi
edited by Brian Hook, Denis Twitchett
Cambridge University Press, 1991
Buku Referensi