The monotone class rank-test-based estimating equations for regression models with right censored data is considered. We introduce an estimator which is a solution of a monotone estimating equation that is an extension of the Gehan test. The estimator is easy to derive, $\sqrt n$-consistent and asymptotically normal under minimal conditions. All monotone estimating equations are characterized, and a simulation study, which shows that our suggested procedure performs well, is included.
"Monotone Estimating Equations for Censored Data." Ann. Statist. 22 (2) 732 - 746, June, 1994. https://doi.org/10.1214/aos/1176325493