by Dwight Waldo ... [et.al.]
Duke University Press, 1970
Buku Teks
Marcel Dekker, Inc, 1990
Buku Teks
edited by John D. Montgomery, William J. Siffin
McGraw-Hill, 1966
Buku Teks SO
Pfiffner, John M., author
Ronald Press, 1960
Buku Teks
edited by Robert T. Golembiewski, Frank Gibson, Geoffrey Y. Cornog
Rand McNally College, 1972
Buku Teks