"Cosmos 186: Display 1966-105A". nssdc.gsfc.nasa.gov. NASA. 27 February 2020. Retrieved 19 April 2020. This article incorporates text from this source, which is in the public domain.
"Cosmos 188: Display 1966-107A". nssdc.gsfc.nasa.gov. NASA. 27 February 2020. Retrieved 19 April 2020. This article incorporates text from this source, which is in the public domain.