TY - JOUR A1 - Yashin, A.I. A1 - Manton, K.G. T1 - Effects of unobserved and partially observed covariate processes on system failure: a review of models and estimation strategies Y1 - 1997 DO - 10.1214/ss/1029963259 JF - Statistical Science VL - 12 IS - 1 SP - 20 EP - -34 ER -