Barish, Norman N., author
Funk & Wagnalls Company, 1951
Buku Teks
Barish, Norman N., author
Institut Ilmu Pemerintahan, 1970
Buku Teks
Koontz, Harold, author
McGraw-Hill, 1976
Buku Teks
Lundy, James L., author
Eurasia Publishing House, 1968
Buku Teks
This, Leslie E.
Addison-Wesley Pub. Co. , 1974
Buku Teks