Jarolimek, John, author
Macmillan, 1968
Buku Teks
Gulati, P., author
Tata McGraw-Hill, 1984
Buku Teks
Barnes, Donald L., author
Burgess, 1969
Buku Teks
Farris, Pamela J., author
New York, 2001
Buku Teks
Levin, Jack, author
Harper & Row, 1973
Buku Teks