Borsboom, Denny
Cambridge university press , 2005
Buku Teks
Krol, Ed
O`Reilly and Associates, 1992
Buku Teks
edited by Alistair Tough, Michael Moss
Chandos Publishing, 2006
Buku Teks
McEwen, F.L.
John Wiley & Sons, 1979
Buku Teks
Koppe, Erik V
Gildprint, Enschede, 2006
Buku Teks