TY  - JOUR
AU  - N. N. Yuberev
TI  - The preservation of the sign of the Green's function of a periodic boundary value problem for a second order difference equation
JO  - Differencialʹnye uravneniâ
PY  - 1968
SP  - 269
EP  - 275
VL  - 4
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1968_4_2_a8/
LA  - ru
ID  - DE_1968_4_2_a8
ER  -