1 mung yellow, 2 mung orangebrown in pair and 10 mung lightgreen in pair on registered cover from Ulan Bator 8-7-1929 to Kalgan (China) refranked with 10 cents Junk, fine/very fine. Mongolia declared independence from China in 1927. Because the Chinese government did not recognize the new governmen,t post from Mongolia to China had to be refranked!