1960-1970s a group of 12 outgoing covers from Mongolia, plus a set
of 1978 Congress-Centrum Hamburg commemorative
1960-1970s a group of 12 outgoing covers from Mongolia, plus a set
of 1978 Congress-Centrum Hamburg commemorative covers.
1960至1970年代一組12件蒙古寄國外封，另附一件1978年Congress-Centrum Hamburg紀念封。
