@book{30073,
	author = {Lettington, Alan, ed.},
	title = {Optical Systems for Space and Defence},
	publisher = {SPIE},
	year = {1990  },
	series = {Proceedings of SPIE; V. 1191},
	address = {Washington, USA},
	url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/1191}
}