CoxBcv.fg               Fay and Graubard (FG) bias-corrected sandwich
                        variance estimator
CoxBcv.fgmr             Hybrid FGMR bias-corrected sandwich variance
                        estimator
CoxBcv.kc               Kauermann and Carroll (KC) bias-corrected
                        sandwich variance estimator
CoxBcv.kcmr             Hybrid KCMR bias-corrected sandwich variance
                        estimator
CoxBcv.mbn              Morel, Bokossa, and Neerchal (MBN)
                        bias-corrected sandwich variance estimator
CoxBcv.mbnmr            Hybrid MBNMR bias-corrected sandwich variance
                        estimator
CoxBcv.md               Mancl and DeRouen (MD) bias-corrected sandwich
                        variance estimator
CoxBcv.mdmr             Hybrid MDMR bias-corrected sandwich variance
                        estimator
CoxBcv.mr               Martingale residual (MR) bias-corrected
                        sandwich variance estimator
CoxBcv.rob              Uncorrected robust sandwich variance estimator
