@article{DAN_1996_351_5_a3,
     author = {\`E. Muhamadiev},
     title = {Bounded solutions and homotopic invariants of systems of nonlinear differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {596--598},
     year = {1996},
     volume = {351},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1996_351_5_a3/}
}