@article{TM_1987_180_a133,
     author = {M. F. Timan and T. N. Semirenko},
     title = {Constructive characteristics of the properties of {Kernels} of integral operators and the behavior of their $s$-numbers},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {217--219},
     year = {1987},
     volume = {180},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1987_180_a133/}
}