@misc{indiciaec78cc701fcc4,
  title = {Chemical composition of sedimentary rocks in Alaska, Idaho, Oregon, and Washington},
  author = {Thelma P. Hill and Marian A. Werner},
  year = {1972},
  doi = {10.3133/pp771},
  url = {https://pubs.usgs.gov/publication/pp771},
  note = {Source identifier: pp771}
}