Dinniss, Heather Harrison
Cambridge Univ. Press, 2014
Buku Teks
Warren, Peter, author
Hodder & Stoughton Ltd., 2013
Buku Teks
edited by Geoffrey Parker
Cambridge University Press, 1995
Buku Referensi
edited by Daniel Ventre
Wiley , 2011
Buku Teks
Daugherty, William E., author
Arno Press, 1958
Buku Teks