Tippett, L.H.C., author
Williams and Norgate, 1952
Buku Teks
Chao, Lincoln L., author
McGraw-Hill, 1974
Buku Teks
Malinvaud, Edmond, author
North Holland , 1987
Buku Teks
Coolican, Hugh, author
Psychology Press, 2014
Buku Teks
Coolican, Hugh, author
Hodder & Stoughton, 2009
Buku Teks