Hiebert, Murray, author
Mc Graw-Hill , 2001
Buku Teks
by Walter J. Wadsworth
Gemini Books, 2000
Buku Referensi
Koestenbaum, Peter
Jossey-Bass Publishers, 1991
Buku Teks
Burns, James McGregor, author
Harper and Row, 1978
Buku Teks
Manning, George, 1943-, author
McGraw-Hill, 2015
Buku Teks