@book{25163,
	author = {Nielsen, Hans, ed.},
	title = {Environment and Pollution Measurement Sensors and Systems},
	publisher = {SPIE},
	year = {1990},
	series = {Proceedings of SPIE; V. 1269},
	address = {Washington, USA},
	url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/1269}
}