Gaba, Jeffrey M., author
United States of America, 1994
Buku Teks
Leeson, John D., author
Pitman, 1995
Buku Teks
Rubenstein, Harvey M.
New York: John Wiley & Sons, 1980
Buku Teks
Schwedt, Georg, author
John Wiley & Sons, 2001
Buku Teks
Schwedt, Georg, author
John Wiley & Sons, 2001
Buku Referensi