@article{GDZPPN001171208, title = {A Note on Polynomial Splines with Free Knots.}, journal = {Numerische Mathematik}, volume = {21}, year = {1973}, pages = {181-184}, zbl = {0265.65006}, url = {http://dml.mathdoc.fr/item/GDZPPN001171208} }
Wulbert, Daniel. A Note on Polynomial Splines with Free Knots.. Numerische Mathematik, Tome 21 (1973) pp. 181-184. http://gdmltest.u-ga.fr/item/GDZPPN001171208/