Mancuso, Joseph, author
Simon & Schuster , 1993
Buku Teks
Keup, Erwin J.
Entrepreneur Press, 2004
Buku Teks
Mather, Hal, author
McGraw-Hill, 1984
Buku Teks
Pickering, Peg, author
Erlangga, 2001
Buku Teks
Humphries, john
Groiler International, 1993
Buku Teks