@article{ND_2012_8_4_a6,
     author = {Alexander P. Ivanov and Nadezhda N. Erdakova},
     title = {On a mechanical lens},
     journal = {Russian journal of nonlinear dynamics},
     pages = {773--781},
     publisher = {mathdoc},
     volume = {8},
     number = {4},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ND_2012_8_4_a6/}
}