Adler, Bill, author
Jones-Irwin, 1985
Buku Teks
Mamoto, Retno Sukardan, author
1999
Artikel Jurnal
Ripley, William Z.
Little, Brown, and Company, 1927
Buku Teks
Pessin, Allan H., author
Business One Irwin, 1990
Buku Referensi
Baruch, Hurd
Acropolis Books ltd., 1971
Buku Teks