Heckman, I. L., author
Charles E. Merrill, 1962
Buku Teks
Schleh, Edward C., author
Prentice-Hall, 1958
Buku Teks
Flippo, Edwin B., author
McGraw-Hill Kogakusha, 1976
Buku Teks
Martin, David M., author
ICSA , 1992
Buku Teks
Jenks, James M.
New Jersey : Alexander Hamilton Institute, Inc,
Buku Referensi