Manley, John F., author
Macmillan, 1976
Buku Teks
Clarke E. Cochran, Lawrence C. Mayer, T.R. Carr, N. Joseph Cayer, Mark J. McKenzie, Laura R. Peck
USA Cengage Learning, 2016
Buku Teks
Bellinger, William Kenneth, author
Routledge, 2007
Buku Teks
Lyon, Leverett S., author
The Brookings Institution, 1940
Buku Teks
Grether, E.T.
Prentice-Hall, 1966
Buku Teks