@misc{indiciae61c374db61c8,
  title = {Contour map of the bedrock surface, Hartford North Quadrangle, Connecticut},
  author = {R. B. Ryder},
  year = {1972},
  doi = {10.3133/i784c},
  url = {https://pubs.usgs.gov/publication/i784C},
  note = {Source identifier: i784C}
}