Ennis, Robert Hugh
Prentice-Hall, 1996
Buku Teks
Halpern, Diane F., author
Lawrence Erlbaum Associates, Publishers, 1996
Buku Teks
Jackson, Debra, author
Wadsworth and Cengage Learning, 2012
Buku Teks
Paul, Richard W.
Prentice-Hall, 2002
Buku Teks
Paul, Richard W., author
Hawker Brownlow Education, 1993
Buku Teks