Boyd, Harper W., Jr., author
Richard D. Irwin, 1970
Buku Teks
Still, Richard R
Prentice Hall International, 1988
Buku Teks
Jones, John G., author
Alexander Hamilton Institute, 1961
Buku Teks
Stanton, William J., author
Richard D. Irwin, 1978
Buku Teks
Stanton, William J., author
Richard D. Irwin, 1964
Buku Teks