1916-1919. A group of 3 large official covers between officials in autonomous Mongolia, each sealed with 3 impressions of the Grand Seal of
1916-1919. A group of 3 large official covers between officials in autonomous Mongolia, each sealed with 3 impressions of the Grand Seal of their office. All seals of Autonomous Mongolia bear the from the Soyombo symbol. The 1916 cover was from the Secretary of Bogda Khan.1916-19年大型公文封3件，蒙古自治時期，收回前清官印，授以“索永布”官印使用。其中1916年一件，由博格達汗秘書發出。
