The Fishbed has come out in fifteen different versions, the most advanced of which is the MiG-21bis. Around 3000 MiG-21 variants still serve in air forces around the world.<ref>[http://www.globalsecurity.org/military/world/russia/mig-21.htm MiG-21 at GlobalSecurity.org]</ref> | The Fishbed has come out in fifteen different versions, the most advanced of which is the MiG-21bis. Around 3000 MiG-21 variants still serve in air forces around the world.<ref>[http://www.globalsecurity.org/military/world/russia/mig-21.htm MiG-21 at GlobalSecurity.org]</ref> |