1. Greven, S., Crainiceanu, C.M., Caffo, B., Reich, D.: Longitudinal functional principal component analysis. Electron. J. Stat. 4, 1022–1054 (2010)
2. Brumback, B.A., Rice, J.A.: Smoothing spline models for the analysis of nested and crossed samples of curves. J. Am. Stat. Assoc. 93, 961–976 (1998)
3. Di, C.Z., Crainiceanu, C.M., Caffo, B.S., Punjabi, N.M.:Multilevel functional principal component analysis. Ann. Appl. Stat. 3, 458–488 (2008)4. Greven, S., Kneib, T.: On the Behaviour of Marginal and Conditional AIC in Linear Mixed Models. Biometrika 97, 773–789 (2010)
4. Guo, W.: Functional mixed effects models. Biometrics 58: 121-128 (2002)
5. Laird, N., Ware, J.H.: Random-effects models for longitudinal data. Biometrics 38, 963–974 (1982)