Gaya APA
DUFFTY, T, M, [. (1992).
CONSTRUCTIVISM and the technology of instruction: .
New Jersey:
Lawrence Erlbaum Assocites.
Gaya MLA
DUFFTY, Thomas, M., [ed.].
"CONSTRUCTIVISM and the technology of instruction:".
New Jersey:
Lawrence Erlbaum Assocites,
1992.
Buku.