1. New efficient estimation and variable selection methods for semiparametric varying-coefficient partially linear models 【已解决，谢谢】
Bo Kai, Runze Li, and Hui Zou
Source: Ann. Statist. Volume 39, Number 1 (2011), 305-332.

2. Shrinkage Estimation of the Varying Coefficient Model
Hansheng Wang, Yingcun Xia. Journal of the American Statistical Association. June 1, 2009, 104(486): 747-757. doi:10.1198/jasa.2009.0138.

3Variable selection for semiparametric varying coefficient partially linear errors-in-variables models  【已解决，谢谢】
[size=-1]P Zhao… - Journal of Multivariate Analysis, 2010 - Elsevier