1. Welty, J. R., 1974, Engineering Heat Transfer, John Wiley, New York.
2. Brenan, K. E., Campbell, S. L., and Petzold, L. R., 1996, Numerical Solution of Initial-Value Problems in Differential Algebraic Equations, SIAM, Philadelphia PA.
3. Campbell, S. L., 1980, Singular Systems of Differential Equations, Research Notes in Mathematics, Vol. 40, Pitman, San Francisco, CA.
4. Campbell, S. L., 1982, Singular Systems of Differential Equations, II, Research Notes in Mathematics, Vol. 60, Pitman, San Francisco, CA.
5. Dai, L., 1989, Singular Control Systems, Springer, Berlin.