@article{PismaZhETF.11.421,
    title = {"Superheterodyne" Amplification of Ultrasound in Semiconductors},
    author = {Gulyaev, Yu. V. and Zil'berman, P. E.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {11},
    issue = {8},
    pages = {421},
    year = {1970},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_26154.shtml},
}