1. Braun, M.: Differential Equations and Their Applications. Springer-Verlag; New York et al. 2nd Edition (1978) 13 + 518 pp. (Applied Mathematical Sciences 15).
2. Christiansen S.: Development of Saw-Tooth Instabilities on a Moving Boundary. Zeit. Angew. Math. Mech. (ZAMM) (Sonderheft, GAMM-Tagung, Regensburg 1984) 65 (1985) T3T3–T3T5.
3. Christiansen, S: A stability analysis of a Eulerian method for some surface gravity wave problems, pp. 75–84 of: Ballmann, J & Rolf J (Eds.): Nonlinear Hyperbolic Equations - Theory, Computation Methods, and Applications (Proceedings of the Second International Conference on Nonlinear Hyperbolic Problems, Aachen, FRG, March 14–18, 1988). Notes on Numerical Fluid Mechanics 24, Friedr. Vieweg k Sohn; Braunschweig, Wiesbaden. (1989) 10 + 718 pp.
4. Christiansen, S: A Stability Analysis of a Eulerian Solution Method for Mo¬ving Boundary Problems in Electrochemical Machining. Jour. Computational Appl. Math., submitted.
5. Christiansen, S: Application of integral equations to an electrochemical machining problem. Mathematisches Forschungsinstitut, Oberwolfach, BRD. Lecture 1980–12–09.