@techreport{oai:repository.dl.itc.u-tokyo.ac.jp:00042612,
 author = {Kubokawa, Tatsuya and Srivastrava, Muni S.},
 month = {Oct},
 note = {application/pdf, 本文フィルはリンク先を参照のこと},
 title = {Optimal Ridge-type Estimators of Covariance Matrix in High Dimension},
 year = {2013}
}