@article{ZNSL_1989_172_a1,
     author = {A. M. Vershik and V. Ya. Gershkovich},
     title = {A nilpotent {Lie} algebras bundle over a non-holonomic manifold {(Nilpotentization)}},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {21--40},
     publisher = {mathdoc},
     volume = {172},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1989_172_a1/}
}