@article{PismaZhETF.6.818,
    title = {Circular Polarization of Photons in the Process $e^+e^-\to$  $2\gamma$ at High Energies},
    author = {Zel'dovich, B. Ya. and Terent'ev, M. V.},
    journal = {Письма в ЖЭТФ},
    volume = {6},
    issue = {8},
    pages = {818},
    year = {1967},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25499.shtml},
}