@misc{indiciaedd62d7a4b2cc,
  title = {Tracking and data relay satellite system configuration and tradeoff study. Volume 4: TDRS system operation and control and telecommunications service system, part 1},
  year = {1972},
  url = {https://ntrs.nasa.gov/citations/19740002694},
  note = {Source identifier: 19740002694}
}