@misc{indiciaeeca6b4ccdba4,
  title = {Computer programs for calculating general- relativistic curvature tensors.},
  author = {Clemens, R. and Fletcher, J. G. and Matzner, R. and Thorne, K. S. and Zimmerman, B. A.},
  year = {1967},
  url = {https://ntrs.nasa.gov/citations/19670050118},
  note = {Source identifier: 19670050118}
}