@article{RM_1984_39_2_a39,
     author = {A. N. Varchenko and S. M. Gusein-Zade},
     title = {The topology of~caustics, wave fronts, and degeneracies of~critical points},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {209--210},
     publisher = {mathdoc},
     volume = {39},
     number = {2},
     year = {1984},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1984_39_2_a39/}
}