Artikel Jurnal
Parkin, Alan C., author
John Wiley & Sons, 1999
Buku Teks
Baddeley, Alan, author
Lawrence Erlbaum Associates, 1990
Buku Teks
Haberlandt, Karl, author
Allyn and Bacon, 1999
Buku Teks
Ashcraft, Mark H., author
Harper Collins, 1994
Buku Teks