@article{ZNSL_1987_163_a11,
     author = {Yu. G. Safarov},
     title = {Riesz means of the distribution function of the eigenvalues of an elliptic operator},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {143--145},
     publisher = {mathdoc},
     volume = {163},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1987_163_a11/}
}