@article{SM_2021_212_5_a3,
     author = {E. D. Gal'kovskii and A. I. Nazarov},
     title = {A~trace formula for higher order ordinary differential operators},
     journal = {Sbornik. Mathematics},
     pages = {676--697},
     publisher = {mathdoc},
     volume = {212},
     number = {5},
     year = {2021},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2021_212_5_a3/}
}