Pontryagin's Type Optimality Conditions for a Distributed Control Problem Arising in Endogenous Growth Theory. - Bernhard Skritek; Tsvetomir Tsachev; Vladimir M. Veliov (LSSC, 2013)

Error estimates for harmonic and biharmonic interpolation splines with annular geometry. - Ognyan Kounchev; Hermann Render; Tsvetomir Tsachev (CoRR, 2022)

Fast algorithms for interpolation with L-splines for differential operators L of order 4 with constant coefficients. - Ognyan Kounchev; Hermann Render; Tsvetomir Tsachev (J. Comput. Appl. Math., 2023)