@article{oai:ismrepo.ism.ac.jp:00033266,
 author = {青山, 博次郎 and Aoyama, Hirojiro},
 issue = {5},
 journal = {統計数理研究所講究録},
 month = {Aug},
 pages = {187--197},
 title = {層別法について},
 volume = {7},
 year = {1951}
}