@article{DAN_1972_205_2_a4,
     author = {A. D. Ioffe},
     title = {An existence theorem for problems of the calculus of variations},
     journal = {Doklady Akademii Nauk},
     pages = {277--280},
     publisher = {mathdoc},
     volume = {205},
     number = {2},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1972_205_2_a4/}
}