TY  - JOUR
AU  - Rachůnková, Irena
TI  - The first kind periodic solutions of differential equations of the second order
JO  - Mathematica slovaca
PY  - 1989
SP  - 407
EP  - 415
VL  - 39
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MASLO_1989__39_4_a6/
LA  - en
ID  - MASLO_1989__39_4_a6
ER  -