@article{MZM_1993_53_4_a4,
     author = {V. G. Zadorozhniy},
     title = {A linear first-order differential equation with ordinary and variational derivatives},
     journal = {Matemati\v{c}eskie zametki},
     pages = {36--44},
     publisher = {mathdoc},
     volume = {53},
     number = {4},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1993_53_4_a4/}
}