@article{Cao Long:2004,
author = "V. Cao Long and P. Goldstein and S. Vu Ngoc",
title = "On existence of solitions for the second harmonic equations of a laser beam",
journal = "Acta Physica Polonica A",
volume = "Vol. 106",
number = "no 6",
pages = "843--852",
year = "2004",
}