共 6 条
[1]
Clark R, 1985, J ED COMPUT RES, V1, P28
[2]
Clark R. E., 1986, HDB RES TEACHING
[3]
CLARK RE, 1983, REV EDUC RES, V53, P445, DOI 10.2307/1170217
[4]
CLARK RE, 1989, ED MEDIA TECHNOLOGY, P19
[5]
Levin H.M., 1986, 86 STANF U STANF ED
[6]
Levin H. M., 1983, COST EFFECTIVENESS P

