1. and . Graph theoretical algorithms for index reduction in circuit simulation. Technical Report Matheon 245, Technical University of Berlin, 2005.
2. and . Element-based Topological Index Reduction for Differential-Algebraic Equations in Circuit Simulation. Technical Report Matheon 246, Technical University of Berlin, 2005.
3. and . Structural analysis for electric circuits and consequences for the MNA. Int. J. Circ. Theor. Appl., 28: 131–162, 2000.
4. Differential-algebraic equation index transformations. SIAM Journal on Scienti.c and Statistic Computing, 9: 39–47, 1988.