Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) KITAZAWA Takeshi and KATO Hiroshi and AKAHORI Kanji,Development of a Digital Portfolio Retrieval System which Reflects Keyword Similarity and an Assessment of its Retrieving Efficiency : A Case Study of ICT Education Using Prior Students' Digital Portfolios,Japan Journal of Educational Technology,13498290,Japan Society for Educational Technology,2005,29,1,1-9,https://cir.nii.ac.jp/crid/1390282680203496320,https://doi.org/10.15077/jjet.kj00003730727