@misc{indiciaea707b3d98b9f,
  title = {Mazama ash in the Northeastern Pacific},
  author = {C.H. Nelson and L.D. Kulm and P.R. Carlson and J. R. Duncan},
  year = {1968},
  doi = {10.1126/science.161.3836.47},
  url = {https://pubs.usgs.gov/publication/70011470},
  note = {Source identifier: 70011470}
}