This paper provides a proof of the asymptotic sufficiency of the ranks in the two sample situation when the observations are censored at the $r$th order statistic. Several important conclusions may then be drawn concerning optimal tests.
@article{1176343464,
author = {Mehrotra, K. G. and Johnson, Richard A.},
title = {Asymptotic Sufficiency and Asymptotically Most Powerful Tests for the Two Sample Censored Situation},
journal = {Ann. Statist.},
volume = {4},
number = {1},
year = {1976},
pages = { 589-596},
language = {en},
url = {http://dml.mathdoc.fr/item/1176343464}
}
Mehrotra, K. G.; Johnson, Richard A. Asymptotic Sufficiency and Asymptotically Most Powerful Tests for the Two Sample Censored Situation. Ann. Statist., Tome 4 (1976) no. 1, pp. 589-596. http://gdmltest.u-ga.fr/item/1176343464/