Factor division: a useful algorithm in model reduction
An alternative approach is given for linear-system reduction by Pade approximation to allow retention of dominant modes. It avoids calculation of system time moments and the solution of Pade equations by simply dividing out the unwanted pole factors. The resulting algorithm is conceptually simple and is seen to be of use in other methods of reduction.
Lucas, T.N. 1983. Factor division: a useful algorithm in model reduction. IEE Proceedings Control Theory and Applications. 130(6): pp.362-364. Available from http://dx.doi.org/10.1049/ip-d:19830060