@incollection{Bal2:99, author = {V. Balakrishnan}, title = {Matrix inequality conditions for canonical factorization of rational transfer function matrices}, booktitle = {Open Problems in Mathematical Systems and Control Theory}, chapter = {7}, year = {1999}, editor = {V. D. Blondel and E. D. Sontag and M. Vidyasagar and J. C. Willems}, publisher = {Springer Verlag}, address = {London} }