@misc{indiciae5a4f9a7dab30,
  title = {ECHO user's guide},
  author = {Landgrebe, D. A. and Kast, J. L. and Swain, P. H. and Davis, B. J. and Spencer, P. W.},
  year = {1977},
  url = {https://ntrs.nasa.gov/citations/19780020634},
  note = {Source identifier: 19780020634}
}