@article{VMUMM_1991_2_a14,
     author = {I. A. Babenko},
     title = {Singularities of the projection of piecewise-linear surfaces in $\mathbf{R}^3$},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {72--75},
     publisher = {mathdoc},
     number = {2},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1991_2_a14/}
}