@misc{indiciaeeb3149d8004c,
  title = {Geological-geophysical investigations of bedrock in the Island Falls quadrangle, Aroostook and Penobscot Counties, Maine},
  author = {E. B. Ekren and Frank C. Frischknecht},
  year = {1967},
  doi = {10.3133/pp527},
  url = {https://pubs.usgs.gov/publication/pp527},
  note = {Source identifier: pp527}
}