@article{PismaZhETF.46.155,
    title = {Second optical harmonic in the ceramic $La_{1.8}Sr_{0.2}Cu0_4$},
    author = {Golovashkin, A. I. and Gorelik, V. S. and Agal'tsov, A. M. and Ivanenko, O. M. and Mitsen, K. V.},
    journal = {Письма в ЖЭТФ},
    volume = {46},
    issue = {4},
    pages = {155},
    year = {1987},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_18538.shtml},
}