@misc{indiciae994f56752558,
  title = {Gravitational lensing by a smoothly variable three-dimensional mass distribution},
  author = {Lee, Man Hoi and Paczynski, Bohdan},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19900052175},
  note = {Source identifier: 19900052175}
}