Gray's Time-Varying Coefficients Model for Posttransplant Survival of Pediatric Liver Transplant Recipients with a Diagnosis of Cancer. - Yi Ren 004; Chung-Chou Ho Chang; Gabriel L. Zenarosa; Heather E. Tomko; Drew Michael S. Donnell; Hyung-Joo Kang; Mark S. Roberts; Cindy L. Bryce (Comput. Math. Methods Medicine, 2013)