TY  - JOUR
AU  - G. I. Natanson
TI  - On the theory of approximation of functions by linear combinations of Sturm--Liouville characteristic functions
JO  - Doklady Akademii Nauk
PY  - 1957
SP  - 263
EP  - 266
VL  - 114
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1957_114_2_a7/
LA  - ru
ID  - DAN_1957_114_2_a7
ER  -