6Hyeonjin Kim,Michael J. Hannafin. Grounded design of web-enhanced case-based activity[J] 2008,Educational Technology Research and Development(2):161~179
7Michael J. Hannafin,Kathleen M. Hannafin,Susan M. Land,Kevin Oliver. Grounded practice and the design of constructivist learning environments[J] 1997,Educational Technology Research and Development(3):101~117