@article{IM2_1967_1_2_a12,
     author = {A. F. Lavrik},
     title = {On functional equations of {Dirichlet} functions},
     journal = {Izvestiya. Mathematics},
     pages = {421--432},
     year = {1967},
     volume = {1},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1967_1_2_a12/}
}