@misc{indiciaefb2bd820dec7,
  title = {Methods and standards for environmental measurement : proceedings of the 8th Materials Research Symposium held at the National Bureau of Standards, Gaithersburg, Maryland, September 20-24, 1976 — Illustration, Page 221},
  year = {1977},
  url = {https://www.biodiversitylibrary.org/page/41747301},
  note = {Source identifier: page-41747301}
}