2012

2013
2008
2002
1999
1961
Sources: http://qrz.ru и http://saeftinghe.blogspot.ru/2011/10/earliest-known-yuri-gagarin-signature.html
Since 1957
Sources: http://qrz.ru и http://saeftinghe.blogspot.ru/2011/10/earliest-known-yuri-gagarin-signature.html