@article{ZNSL_2007_350_a1,
     author = {I. N. Demshin and V. A. Shlyk},
     title = {Metric characteristics of normal in {Grotzsch's} sense ring's domains with radial slits in space},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {17--25},
     publisher = {mathdoc},
     volume = {350},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2007_350_a1/}
}