Higham, N. J., author
Routledge, 2006
Buku Teks
Hollister, C. Warren, author
John Wiley & Sons, 1968
Buku Teks
Scott, Jonathan F., author
Appleton Century Croffs, 1933
Buku Teks
Brown, Peter, 1935-, author
Wiley-Blackwell, 2013
Buku Teks
edited by Peter Widdowson
Methuen , 1982
Buku Teks