Stamp of the Soviet Union, International Letter Week, 1991, CPA 6347.
Lembit Lõhmus / Лембит Лыхмус; original uploader was <a href="https://ru.wikipedia.org/wiki/User:Agent001" class="extiw" title="ru:User:Agent001">Agent001</a> at <a class="external text" href="https://ru.wikipedia.org">ru.wikipedia</a>
1991; 22 April 2008 (original upload date)
Electronic catalog "Stamps of the Soviet Land" / <a rel="nofollow" class="external text" href="http://tracker.nnm.ru/marki_strany_sovetov_elektronnyj_katalog_pochtovyh_marok">Электронный каталог „Марки страны Советов”</a>; transferred from <a class="external text" href="https://ru.wikipedia.org">ru.wikipedia</a>; transfered to Commons by <a href="//commons.wikimedia.org/wiki/User:Mariluna" title="User:Mariluna">User:Mariluna</a> using <a rel="nofollow" class="external text" href="http://tools.wikimedia.de/~magnus/commonshelper.php">CommonsHelper</a>.