@article{1077376068,
author = {Krall, Allan M.},
title = {Second order ordinary differential operators with general
boundary conditions},
journal = {Duke Math. J.},
volume = {32},
number = {1},
year = {1965},
pages = { 617-625},
language = {en},
url = {http://dml.mathdoc.fr/item/1077376068}
}
Krall, Allan M. Second order ordinary differential operators with general
boundary conditions. Duke Math. J., Tome 32 (1965) no. 1, pp. 617-625. http://gdmltest.u-ga.fr/item/1077376068/