@article{DAN_1971_200_5_a7,
     author = {B. N. Sadovskii},
     title = {Application of topological methods in the theory of periodic solutions of nonlinear differential-operator equations of neutral type},
     journal = {Doklady Akademii Nauk},
     pages = {1037--1040},
     publisher = {mathdoc},
     volume = {200},
     number = {5},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_200_5_a7/}
}