著者名,論文名,雑誌名,ISSN,出版者名,出版日付,巻,号,ページ,URL,URL(DOI) Michel C. Desmarais,Mapping question items to skills with non-negative matrix factorization,ACM SIGKDD Explorations Newsletter,1931-0145,Association for Computing Machinery (ACM),2012-05,13,2,30-36,https://cir.nii.ac.jp/crid/1363951794966895232,https://doi.org/10.1145/2207243.2207248