@misc{indiciaefa4f3a897a56,
  title = {Trajectory optimization using regularized variables.},
  author = {Lewallen, J. M. and Szebehely, V. and Tapley, B. D.},
  year = {1968},
  url = {https://ntrs.nasa.gov/citations/19680057715},
  note = {Source identifier: 19680057715}
}