@misc{indiciaec9893b491723,
  title = {Map showing free-air gravity anomalies off the western coast of Africa Nigeria to Gabon},
  author = {D. W. Folger and J.R. McCullough and B.J. Irwin and G.R. Driscoll and C.M. Delorey and C. F. Polloni},
  year = {1990},
  doi = {10.3133/mf2098f},
  url = {https://pubs.usgs.gov/publication/mf2098F},
  note = {Source identifier: mf2098F}
}