@article{oai:bunkyo.repo.nii.ac.jp:00003337,
 author = {Bamford, Julian},
 journal = {情報研究, Information and Communication Studies},
 month = {1987-01-01, 2012-01-17},
 pages = {143--149},
 title = {How Much in How Long? : Estimating the Length of Time It Takes to Learn a Foreign Language},
 volume = {8},
 year = {}
}