@article{CMFD_2006_16_a5,
     author = {I. I. Kosenko},
     title = {Topological degree and approximation of solutions for nonregular problems of mechanics: {Oscillations} of satellites on elliptic orbits},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {68--95},
     publisher = {mathdoc},
     volume = {16},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2006_16_a5/}
}