@misc{indiciaec104cef1c6ab,
  title = {FREQ: A computational package for multivariable system loop-shaping procedures},
  author = {Giesy, Daniel P. and Armstrong, Ernest S.},
  year = {1989},
  url = {https://ntrs.nasa.gov/citations/19890019676},
  note = {Source identifier: 19890019676}
}