Reynolds, Lloyd G., author
Yale University Press, 1971
Buku Teks
Angresano, James, author
Prentice-Hall, 1991
Buku Teks
Reynold, Lloyd George
McGraw-Hill, 1981
Buku Teks
Rosser, J. Barkley, author
McGraw-Hill, 1996
Buku Teks
Chilcote, Ronald H., author
Routledge, 2000
eBooks