@article{DAN_1981_261_3_a6,
     author = {A. S. Merkur'ev},
     title = {On the norm residue symbol of degree~$2$},
     journal = {Doklady Akademii Nauk},
     pages = {542--547},
     publisher = {mathdoc},
     volume = {261},
     number = {3},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_261_3_a6/}
}