@misc{indiciae8f4de34a135c,
  title = {Future long-range transports: Prospects for improved fuel efficiency},
  author = {Nagel, A. L. and Alford, W. J., Jr. and Dugan, J. F., Jr.},
  year = {1975},
  url = {https://ntrs.nasa.gov/citations/19750009267},
  note = {Source identifier: 19750009267}
}