Sun, Xiaoxiao, David Dalpiaz, Di Wu, Jun S. Liu, Wenxuan Zhong, and Ping Ma. "Statistical inference for time course RNA-Seq data using a negative binomial mixed-effect model." BMC Bioinformatics, 17(1):324, 2016.
Chong Gu. Model diagnostics for smoothing spline ANOVA models. Canadian Journal of Statistics, 32(4):347-358, 2004.
Chong Gu. Smoothing spline ANOVA models. Springer, second edition, 2013.
Chong Gu and Ping Ma. Optimal smoothing in nonparametric mixed-effect models. Annals of Statistics, pages 1357-1379, 2005a.
Wood (2001) mgcv:GAMs and Generalized Ridge Regression for R. R News 1(2):20-25