Russell, J. Thomas
Prentice-Hall, 1999
Buku Teks
Hotchkiss, George Burton
Alexander Hamilton Institute , 1961
Buku Teks
White, Roderick
McGraw-Hill, 2000
Buku Teks
White, Roderick
McGraww-Hill , 2000
Buku Teks
Wells, William D.
Prentice-Hall, 2000
Buku Teks