@article{CMFD_2010_35_a6,
     author = {P. Mironescu},
     title = {$\mathbb S^1${-Valued} {Sobolev} maps},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {86--100},
     publisher = {mathdoc},
     volume = {35},
     year = {2010},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2010_35_a6/}
}