Seelye, Elwyn E.
New York: John Wiley & Sons, 1954
Buku Teks
Utley, Rose A.
Jones and Bartlett , 2011
Buku Teks
Hannah Cobb, editors
Springer, 2012
eBooks
Susan K. Kovar ... [and others]
McGraw-Hill, 2012
Buku Teks
Baddeley, Alan
Lawrence Erlbaum Associates, 1990
Buku Teks