@article{VMUMM_1991_4_a13,
     author = {A. Ya. Sagomonyan},
     title = {Catastrophic shear in the problem of target piercing},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {58--64},
     year = {1991},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1991_4_a13/}
}