Sequential nonparametrics and semiparametrics: Theory, implementation   and applications to clinical trials
  One of Pranab K. Sen's major research areas is sequential nonparametrics and semiparametrics and their applications to clinical trials, to which he has made many important contributions. Herein we review a number of these contributions and related developments. We also describe some recent work on nonparametric and semiparametric inference and the associated computational methods in time-sequential clinical trials with survival endpoints. 
Tze Leung Lai, Zheng Su