@article{1183506033, author = {Bellman, Richard}, title = {Almost orthogonal series}, journal = {Bull. Amer. Math. Soc.}, volume = {50}, number = {12}, year = {1944}, pages = { 517-519}, language = {en}, url = {http://dml.mathdoc.fr/item/1183506033} }
Bellman, Richard. Almost orthogonal series. Bull. Amer. Math. Soc., Tome 50 (1944) no. 12, pp. 517-519. http://gdmltest.u-ga.fr/item/1183506033/