@article{ZNSL_2023_527_a4,
     author = {A. A. Lunev and M. M. Malamud},
     title = {On an asymptotic expansion of the characteristic determinant for $2 \times 2$ {Dirac} type systems},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {94--136},
     publisher = {mathdoc},
     volume = {527},
     year = {2023},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2023_527_a4/}
}