Murphy-Morris, Jeanine (8 January 2008). "Operational Land Imager"(PDF). U.S. Geological Survey. Archived from the original(PDF) on 1 January 2017. Retrieved 22 March 2018.
Murphy-Morris, Jeanine (8 January 2008). "Operational Land Imager"(PDF). U.S. Geological Survey. Archived from the original(PDF) on 1 January 2017. Retrieved 22 March 2018.