@article{CTT100571179,
  author = {K. Kashima and Y. Yamamoto},
  title = {On standard H_infinity control problems for systems with infinitely many unstable poles},
  journal = {Systems and Control Letters},
  year = 2008,
}

@article{CTT100571180,
  author = {K. Kashima and Y. Yamamoto},
  title = {Finite rank criteria for H_infinity control of infinite-dimensional systems},
  journal = {IEEE Transactions on Automatic Control},
  year = 2008,
}