TY  - JOUR
AU  - Eid, M.H.
AU  - Anwar, M.N.
AU  - El-Serafi, S.A.
TI  - Approximate methods for calculating the period of oscillations for the generalized Lienard's differential equation
JO  - Portugaliae mathematica
PY  - 1982
SP  - 71
EP  - 81
VL  - 41
IS  - 1-4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/PORMA_1982__41_1-4_115484/
LA  - en
ID  - PORMA_1982__41_1-4_115484
ER  -