@article{CMFD_2024_70_3_a4,
     author = {K. N. Zhuikov and A. Yu. Savin},
     title = {On two methods of determining $\eta$-invariants of elliptic boundary-value problems},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {403--416},
     publisher = {mathdoc},
     volume = {70},
     number = {3},
     year = {2024},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2024_70_3_a4/}
}