@article{Polyak_1963,
    doi = {10.1016/0041-5553(63)90382-3},
    url = {https://doi.org/10.1016%2F0041-5553%2863%2990382-3},
    year = {1963},
    month = {jan},
    publisher = {Elsevier {BV}},
    volume = {3},
    number = {4},
    pages = {864--878},
    author = {B.T. Polyak},
    title = {Gradient methods for the minimisation of functionals},
    journal = {{USSR} Computational Mathematics and Mathematical Physics}
}

@article{Polyak_1963, doi = {10.1016/0041-5553(63)90382-3}, url = {https://doi.org/10.1016%2F0041-5553%2863%2990382-3}, year = {1963}, month = {jan}, publisher = {Elsevier {BV}}, volume = {3}, number = {4}, pages = {864--878}, author = {B.T. Polyak}, title = {Gradient methods for the minimisation of functionals}, journal = {{USSR} Computational Mathematics and Mathematical Physics} }