@article{FAA_2009_43_3_a2,
     author = {M. Sh. Birman and V. A. Sloushch},
     title = {Two-Sided {Estimates} for the {Trace} of the {Difference} of {Two} {Semigroups}},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {26--32},
     publisher = {mathdoc},
     volume = {43},
     number = {3},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_2009_43_3_a2/}
}