R. B. Schlottmann

The Accuracy of the Born and Ray Approximations in Time-Distance Helioseismology

A. Kosovichev, A. Birch, G. Price, 2001 .

Helioseismic Fr\'{e}chet Traveltime Kernels in Spherical Coordinates

A. Kosovichev, R. B. Schlottmann, 2011, 1105.4619.

Extended Diffraction Tomography

R. B. Schlottmann, 2007, 0905.0238.