Iain Hay
McGraw-Hill , 2011
Buku Teks
Alexander, Roy, 1925-
American Management Association;, 2009
eBooks
Kvern, Martin Olav
Macromedia Press, 1998
Buku Teks
Sargent III, Murray
Addison-Wesley, 1981
Buku Teks
Bello, Ignacio
McGraw-Hill, 2006
Buku Teks