@misc{indiciae4b7b6dc5ed7b,
  title = {Munsell color value as related to organic carbon in Devonian shale of Appalachian basin},
  author = {John W. Hosterman and Sallie I. Whitlow},
  year = {1981},
  doi = {10.1306/2f9197ce-16ce-11d7-8645000102c1865d},
  url = {https://pubs.usgs.gov/publication/70011956},
  note = {Source identifier: 70011956}
}