@article{2994,
author = {Eid, M.H. and Anwar, M.N. and El-Serafi, S.A.},
title = {Approximate methods for calculating the period of oscillations for the generalized Lienard's differential equation},
journal = {Portugaliae mathematica},
volume = {41},
year = {1982},
pages = {71-81},
zbl = {0564.34038},
mrnumber = {0766840},
language = {en},
url = {http://dml.mathdoc.fr/item/2994}
}
Eid, M.H.; Anwar, M.N.; El-Serafi, S.A. Approximate methods for calculating the period of oscillations for the generalized Lienard's differential equation. Portugaliae mathematica, Tome 41 (1982) pp. 71-81. http://gdmltest.u-ga.fr/item/2994/