@misc{indiciae62eef432e15d,
  title = {Singularity perturbed zero dynamics of nonlinear systems},
  author = {Isidori, A. and Sastry, S. S. and Kokotovic, P. V. and Byrnes, C. I.},
  year = {1992},
  url = {https://ntrs.nasa.gov/citations/19930033374},
  note = {Source identifier: 19930033374}
}