@inproceedings{xin2018nearly,
title={Nearly Optimal Stochastic Approximation for Online Principal Subspace Estimation},
author={Xin Liang, Zhen-Chen Guo, Ren-Cang Li, and Wen-Wei Lin},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20171118011441008772855},
year={2018},
}