no. 6
On pointwise stability of cubic smoothing splines with nonuniform sampling points
ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique, Tome 25 (1991) no. 6, pp. 671-692. 
@article{M2AN_1991__25_6_671_0,
     author = {Anderssen, R. S. and de Hoog, F. R. and Wahlbin, L. B.},
     title = {On pointwise stability of cubic smoothing splines with nonuniform sampling points},
     journal = {ESAIM: Mathematical Modelling and Numerical Analysis - Mod\'elisation Math\'ematique et Analyse Num\'erique},
     pages = {671--692},
     publisher = {AFCET - Gauthier-Villars},
     volume = {25},
     number = {6},
     year = {1991},
     zbl = {0758.41012},
     mrnumber = {1135989},
     language = {en},
     url = {archive.numdam.org/item/M2AN_1991__25_6_671_0/}
}
Anderssen, R. S.; de Hoog, F. R.; Wahlbin, L. B. On pointwise stability of cubic smoothing splines with nonuniform sampling points. ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique, Tome 25 (1991) no. 6, pp. 671-692. http://archive.numdam.org/item/M2AN_1991__25_6_671_0/

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