Yule, George, author
Cambridge University Press, 2018
Buku Teks
Central Education Research Institute,
Multimedia
Currie, R.M., author
Pitman, 1972
Buku Teks
Klein, Josephine, 1926-, author
Routledge and Kegan Paul, 1956
Buku Teks
Bruner, Jerome, author
John Wiley & Sons, 1956
Buku Teks