Huntington, Samuel P., author
Vakils Feffer and Simons Private, 1968
Buku Teks
Largay III, James A., author
John Wiley & Sons, 1976
Buku Teks
Roeber, Richard J.C., author
Addison-Wesley, 1973
Buku Teks
Holloway, Robert J., author
John Wiley & Sons, 1968
Buku Teks
Bell, Robert R.
Prentice Hall Inc., 1966
Buku Teks