@misc{indiciae5931fb071056,
  title = {Computer programs for plotting spot-beam coverages from an earth synchronous satellite and earth-station antenna elevation angle contours},
  author = {Stagl, T. W. and Singh, J. P.},
  year = {1972},
  url = {https://ntrs.nasa.gov/citations/19730004176},
  note = {Source identifier: 19730004176}
}