Novit, Mitchell S.
Prentice-Hall, 1979
Buku Teks
Werther, William B., author
McGraw-Hill , 1989
Buku Teks
Werther, William B., author
McGraw-Hill, 1996
Buku Teks
Werther, William B., author
McGraw-Hill, 1986
Buku Teks
Northcott, C.H.
Philoshopical Library , 1956
Buku Teks