Louka, Elli, author
Edward Elgar, 2011
Buku Teks
edited by Gro Nystuen, Stuart Casey-Maslen, Annie Golden Bersagel
Cambridge University Press, 2015
Buku Teks
Griffiths, Peter, author
Edward Arnold, 1987
Buku Teks
Tahkur, Ramesh, author
Westview Press, 1986
Buku Referensi
Macmillan Press , 1998
Buku Teks