@misc{indiciae16edd8898cd3,
  title = {Bounded-input bounded-output stability of nonlinear time-varying differential systems.},
  author = {Liu, R. and Varaiya, P. P.},
  year = {1966},
  url = {https://ntrs.nasa.gov/citations/19670037148},
  note = {Source identifier: 19670037148}
}