@misc{indiciaea28f4fd1c9cc,
  title = {The morphological continuum in solid propellant grain design.},
  author = {Billheimer, J. S. and Wagner, F. R.},
  year = {1968},
  url = {https://ntrs.nasa.gov/citations/19680063297},
  note = {Source identifier: 19680063297}
}