Duechs, D. Theory, Max Planck Institute for Plasma Physics, Max Planck Society;
Finckenstein, K. F. v., & Duechs, D. (1976). Convergence of Difference Methods for Quasilinear Diffusion Problems in Cylindrical Symmetry. Methoden und Verfahren der mathematischen Physik, Bd. 15, 75-89.