@article{PismaZhETF.22.143,
    title = {Observation of nonresonant six-photon processes in a calcite crystal},
    author = {Akhmanov, S. A. and Martynov, V. A. and Saltiel, S. M. and Tunkin, V. G.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {22},
    issue = {3},
    pages = {143},
    year = {1975},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_23280.shtml},
}