@article{PismaZhETF.21.114,
    title = {Mechanism of excitation of combination frequencies in ionospheric plasma},
    author = {Kotik, D. S. and Trakhtengerts, V. Yu.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {21},
    issue = {2},
    pages = {114},
    year = {1975},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_22262.shtml},
}