@misc{indiciaea1751bc65b3c,
  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 170},
  year = {1977},
  url = {https://www.biodiversitylibrary.org/page/41747250},
  note = {Source identifier: page-41747250}
}