@article{MZM_1968_3_6_a1,
     author = {V. E. Govorov},
     title = {Derivatives of the radicals of moduli},
     journal = {Matemati\v{c}eskie zametki},
     pages = {633--642},
     publisher = {mathdoc},
     volume = {3},
     number = {6},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1968_3_6_a1/}
}