1. Babuska, I., Präger, M, Vitasék, E.: Numerical processes in differential equations. New York: Interscience 1966.
2. Broyden, C. G.: Quasi-Newton methods and their application to function minimisation. Math. Comp. 21, 368–381 (1967).
3. Bulirsch, R.: Die Mehrzielmethode zur numerischen Lösung von nichtlinearen Randwertproblemen und Aufgaben der optimalen Steuerung. Report der Carl-Cranz-Gesellschaft 1971.
4. Bulirsch, R., Stoer, J.: Numerical treatment of ordinary differential equations by extrapolation methods. Num. Math. 8, 1–13 (1966).
5. Bulirsch, R., Stoer, J., Deuflhard, P.: Numerical solution of nonlinear two-point boundary value problems I. Handbook Series Approximation, Num. Math.