@article{oai:repository.dl.itc.u-tokyo.ac.jp:00016512,
 author = {Kikuchi, Shota},
 journal = {言語情報科学},
 month = {Mar},
 pages = {19--35},
 title = {On Whom in American English from 1990 : A Study Based on the Corpus of Contemporary American English},
 volume = {12},
 year = {2014}
}