@article{RM_2006_61_4_a9,
     author = {N. B. Melnikov},
     title = {Extremal properties of singularities of {Goursat} distributions},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {778--779},
     year = {2006},
     volume = {61},
     number = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_2006_61_4_a9/}
}