Fox, William M
Jossey Bass, 1987
Buku Teks
Robertson, S. Ian, author
Psychology Press, 2001
Buku Teks
Hodnett, Edward
Harper & Brothers, 1955
Buku Teks
Briggs, William, author
Society for Industrial and Applied Mathematics, 2005
eBooks
O`connor, Joseph, author
Thorsons, 1997
Buku Teks