edited by Douglas A. Grouws
Macmillan Library Reference, 1992
Buku Referensi
Wiersma, William, author
Pearson, 2009
Buku Teks
Freebody, Peter, author
SAGE Publications, 2003
Buku Teks
edited by Merlin C. Wittrock; a project of the American Educational Research Association
Macmillan Library Reference USA, 1986
Buku Referensi
Schmuck, Richard A., author
Skylight, 1998
Buku Teks