Michael Ungar, editor
Springer, 2012
eBooks
Thompson, Arthur A., 1940-, author
Prentice-Hall, 1989
Buku Teks
Seckler-Hudson, Catheryn, author
Washington, D.C., The American University Press
Buku Teks
Batley, Sue, author
Chandos, 2014
eBooks
Livadas, Panos E., author
Prentice/Hall International, 1990
Buku Teks