Smith, Nick, author
John Wiley & Sons, 2011
Buku Teks
Zimmerman, Neal, author
John Wiley & Sons, 1996
Buku Teks
O`Neil, John R., author
McGraw-Hill, 1995
Buku Teks
Ennico, Cliff, author
American Management Association, 2007
eBooks
Poissant, Charles-Albert
Pustaka Tangga, 1993
Buku Teks