9Hughes M, Daykin N. Towards constructivism: investigating students' perceptions and learning as a result of using an online environment [J]. Innovations in Education and Teaching International. 2002, 39: 217-224.
10Larochelle M, Bednarz N. Constructivism and education: Beyond epistemological correctness [M]. Cambridge, UK: Cambridge University Press, 1998: 3- 20.