@article{PismaZhETF.6.606,
    title = {Real Part of Scattering Amplitude at High Energies and Dispersion Sum Rules},
    author = {Khalfin, L. A.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {6},
    issue = {4},
    pages = {606},
    year = {1967},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25344.shtml},
}