@article{PismaZhETF.16.228,
    title = {Observation of the Free-exciton Spectrum at Submillimeter Wavelengths},
    author = {Gershenzon, E. M. and Gol'tsman, G. N. and Ptitsina, N. G.},
    journal = {Письма в ЖЭТФ},
    volume = {16},
    issue = {4},
    pages = {228},
    year = {1972},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_26807.shtml},
}