@article{RM_2010_65_3_a7,
     author = {A. N. Kurbatskii},
     title = {Singularities of the transitivity zone of surfaces with boundaries in~$\mathbb R^3$},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {583--585},
     publisher = {mathdoc},
     volume = {65},
     number = {3},
     year = {2010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_2010_65_3_a7/}
}