@article {tu2005bartlett, title = {A Bartlett type correction for Rao{\textquoteright}s score test in Cox regression model}, journal = {Sankhy\=a: The Indian Journal of Statistics}, year = {2005}, pages = {722{\textendash}735}, publisher = {JSTOR}, author = {Tu, Dongsheng and Chen, Jiahua and Shi, Peide and Wu, Yaohua} }