@misc{indiciae59a2386a45b0, 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 620}, year = {1977}, url = {https://www.biodiversitylibrary.org/page/41747700}, note = {Source identifier: page-41747700} }