【题名】：Penalized spline estimation for partially linear single-index models
【作者】：Yu, Y., & Ruppert, D.
【期刊名,年份,卷(期),页码】：Journal of the American Statistical Association, 97, 1042–1054.
【全文链接】：http://www.tandfonline.com/doi/abs/10.1198/016214502388618861