@misc{indiciae16801fe18fca,
  title = {Methods of extending signatures and training without ground information},
  author = {Henderson, R. G. and Thomas, G. S. and Nalepka, R. F.},
  year = {1975},
  url = {https://ntrs.nasa.gov/citations/19750018403},
  note = {Source identifier: 19750018403}
}