Kaplan, Burton, author
Prentice-Hall, 1995
Buku Teks
Barker, Eric, author
Gramedia Pustaka Utama, 2019
Buku Teks
Tracy, Brian, author
John Wiley & Sons, 2003
Buku Teks
Monath, Norman
Pink Books, 2004
Buku Teks
Maxwell, John C., author
Menuju Insan Cemerlang, 2014
Buku Teks