@misc{indiciae7981515ad21d,
  title = {Prolongation structures of nonlinear evolution equations. II},
  author = {Estabrook, F. B. and Wahlquist, H. D.},
  year = {1976},
  url = {https://ntrs.nasa.gov/citations/19770028626},
  note = {Source identifier: 19770028626}
}