B. R. Vainberg, “Parametrix and asymptotics of the spectral function of differential operators in $\mathbf R^n$”, Math. USSR-Sb., 58:1 (1987), 245–265
R. G. Novikov, “Reconstruction of a two-dimensional Schrödinger operator from the scattering amplitude for fixed energy”, Funct. Anal. Appl., 20:3 (1986), 246–248
V. A. Kondrat'ev, O. A. Oleinik, “Precise Hölder exponents for a generalized solution of the Dirichlet problem for the biharmonic equation that are defined by the geometry of the domain”, Russian Math. Surveys, 40:4 (1985), 193–194
V. I. Arnol'd, M. I. Vishik, I. M. Gel'fand, Yu. V. Egorov, A. S. Kalashnikov, A. N. Kolmogorov, S. P. Novikov, S. L. Sobolev, “Ol'ga Arsen'evna Oleinik (on her sixtieth birthday)”, Russian Math. Surveys, 40:5 (1985), 267–287