Shin-ichi Tsukada. Equivalence testing of mean vector and covariance matrix for multi-populations under a two-step monotone incomplete sample. JOURNAL OF MULTIVARIATE ANALYSIS. 2014. 132. 183-196
Shin-ichi Tsukada. Unbiased estimator for a covariance matrix under two-step monotone incomplete sample. COMMUNICATIONS IN STATISTICS-THEORY AND METHODS. 2014. 43. 8. 1613-1629