@article{GDZPPN001177982, title = {Natural Spline Functions, Their Associated Eigenvalue Problem.}, journal = {Numerische Mathematik}, volume = {42}, year = {1983}, pages = {107-118}, zbl = {0522.41011}, url = {http://dml.mathdoc.fr/item/GDZPPN001177982} }
Utreras, Florencio. Natural Spline Functions, Their Associated Eigenvalue Problem.. Numerische Mathematik, Tome 42 (1983) pp. 107-118. http://gdmltest.u-ga.fr/item/GDZPPN001177982/