@article{ND_2013_9_1_a3,
     author = {Alexandr S. Sumbatov},
     title = {Lagrange's equations in nonholonomic mechanics},
     journal = {Russian journal of nonlinear dynamics},
     pages = {39--50},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ND_2013_9_1_a3/}
}