1. (1) Defense Meteorological Satellite Program (DMSP) http://www.ngdc.noaa.gov/dmsp/http://earthobservatory.nasa.gov/IOTD/view.php?id=896]
2. (2) Cities at night: The view from space http://earthobservatory.nasa.gov/Features/CitiesAtNight/
3. (3) The gateway to astronaut photography of Earth http://eol.jsc.nasa.gov/
4. (4) Kitsinelis, S.: Light Sources: Technologies and Applications, Taylor and Francis, 2010 ISBN 978-1439820797
5. (5) Kitsinelis, S.: The Right Light: Matching Technologies to Needs and Applications, Taylor and Francis, 2012, ISBN 978-1439899311