Metzler, Lloyd A.
W.W. Norton & Company Inc. , 1948
Buku Teks SO
edited by William F. Sharpe and Catryn M. Cootner
Prentice-Hall, 1982
Buku Teks SO
Pfiffner, John M.
Ronald Press, 1960
Buku Teks
edited by Robert T. Golembiewski, Frank Gibson, Geoffrey Y. Cornog
Rand McNally College, 1972
Buku Teks
Simon, Herbert A.
Alfred A. Knopf, 1973
Buku Teks