by Robert Bartley [and others]
ISEAS, 1994
Buku Teks
Patterson, Thomas E., author
McGraw-Hill, 203
Buku Teks
Ranney, Austin, author
Harcourt, Brace and Company, 1956
Buku Teks
Laski, Harold J., author
George Allen and Unwin, 1949
Buku Teks
McConnell, Grant, author
Alfred A. Knopf, 1967
Buku Teks