Tsvetkova, T. A., and I. V. Bugaenko. “Seismotomography of the Mantle under the East European Platform: Mantle Velocity Boundaries”. Geofizicheskiy Zhurnal, vol. 34, no. 5, Oct. 2012, pp. 161-72, doi:10.24028/gzh.0203-3100.v34i5.2012.116672.