Cha, Seung Eun; Jun, Soo Jin; Kwon, Dai Yong; Kim, Han Sung; Kim, Seung Bum; Kim, Ja Mee; Kim, Young Ae; Han, Sun Gwan; Seo, Soon Sik; Jun, Woo Cheon, et al.
ArticleIssue Date2011CitationCOMPUTERS & EDUCATION, v.56, no.4, pp.990 - 1002PublisherPERGAMON-ELSEVIER SCIENCE LTD