@article{oai:ismrepo.ism.ac.jp:00033172,
 author = {青山, 博次郎 and Aoyama, Hirojiro},
 issue = {6},
 journal = {統計数理研究所講究録},
 month = {Sep},
 pages = {247--253},
 title = {二回抽出法について},
 volume = {6},
 year = {1950}
}