1. Adams, R.A.: Sobolev Spaces. No. 65 in Pure and Applied Mathematics. Academic, New York/London (1975)
2. Bender, D., Laub, A.: The linear quadratic optimal regulator problem for descriptor systems. IEEE Trans. Autom. Control 32, 672–688 (1987)
3. Berger, T.: Bohl exponent for time-varying linear differential-algebraic equations. Int. J. Control 85(10), 1433–1451 (2012)
4. Berger, T.: On differential-algebraic control systems. Ph.D. thesis, Institut für Mathematik, Technische Universität Ilmenau, Universitätsverlag Ilmenau, Ilmenau (2013)
5. Berger, T.: Zero dynamics and funnel control of general linear differential-algebraic systems (2013). Submitted for publication. Preprint available from the website of the author