1. T. Alishenas,Zur numerische Behandlung, Stabilisierung durch Projektion und Modellierung mechanischer Systeme mit Nebenbedingungen und Invarianten, Royal Institute of Technology, Stockholm, Ph.D. thesis, 1992.
2. A. Barrlund,Constrained least squares methods for linear timevarying DAE systems, Numer Math., 60 (1991), pp. 145–161.
3. A. Barrlund,Constrained least squares methods for non-linear differential algebraic systems, Report UMINF-91.15, University of Umeå, 1991.
4. A. Barrlund,Numerical Solution of higher index differential/algebraic systems, University of Umeå, Ph.D. thesis, 1991.
5. K. E. Brenan, S. L. Campbell and L. R. Petzold,Numerical Solution of Initial Value Problems in Ordinary Differential Equations, North Holland Publishing Co. 1989.