edited by Ian Ousby
Cambridge University Press, 1993
Buku Referensi
edited by A.W. Ward and A.R. Waller
Macmillan, 1939
Buku Teks
Peters, Pam
Cambridge University Press, 2006
Buku Referensi
Sampson, George
University Press, 1949
Buku Referensi
edited by Malcolm Godden and Michael Lapidge
Cambridge University Press, 1991
Buku Teks