@inproceedings{inproceedings6fcc028f,
title   = {On the existence of periodic solutions for the equation x 'DOIS PONTOS'+f (x)x 'PONTO' p sobre q+g (x) =0},
author = {Guidorizzi, Hamilton L.},
year = {1989},
publisher = {SBM},
booktitle   = {Seminário Brasileiro de Análise}
}