@article{PismaZhETF.51.121,
    title = {Decay of femtosecond pulses during amplification in single-mode optical fibers doped with $Er^{3+}$  ions},
    author = {Grudinin, A. B. and Dianov, E. M. and Korobkin, D. V. and Makarenko, A. Yu. and Prokhorov, A. M. and Khrushchev, I. Yu.},
    journal = {Письма в ЖЭТФ},
    volume = {51},
    issue = {3},
    pages = {121},
    year = {1990},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17202.shtml},
}