@misc{indiciaea72435145cab,
  title = {An improved gravity model for Mars: Goddard Mars Model-1 (GMM-1)},
  author = {Smith, D. E. and Lerch, F. J. and Nerem, R. S. and Zuber, M. T. and Patel, G. B. and Fricke, S. K. and Lemoine, F. G.},
  year = {1993},
  url = {https://ntrs.nasa.gov/citations/19940018809},
  note = {Source identifier: 19940018809}
}