@article{MZM_2010_88_2_a7,
     author = {Kh. D. Ikramov},
     title = {Criteria for {Unitary} {Congruence} of {Complex} $2\times 2$ {Matrices}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {249--260},
     publisher = {mathdoc},
     volume = {88},
     number = {2},
     year = {2010},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2010_88_2_a7/}
}