@article{SM_1991_68_1_a7,
     author = {Yu. I. Sapronov},
     title = {Semiregular corner singularities of smooth functions},
     journal = {Sbornik. Mathematics},
     pages = {151--163},
     publisher = {mathdoc},
     volume = {68},
     number = {1},
     year = {1991},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1991_68_1_a7/}
}