@article{GDZPPN002530694,
title = {An arithmetical theorem concerning linear differential-difference equations.},
journal = {Publications de l'Institut Math\'ematique [Elektronische Ressource]},
volume = {4},
year = {1952},
pages = {121-128},
zbl = {0047.08102},
language = {en},
url = {http://dml.mathdoc.fr/item/GDZPPN002530694}
}
Popken, J. An arithmetical theorem concerning linear differential-difference equations.. Publications de l'Institut Mathématique [Elektronische Ressource], Tome 4 (1952) pp. 121-128. http://gdmltest.u-ga.fr/item/GDZPPN002530694/