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In China, the languages of the Tajiks have no official written form. The great majority of Chinese Tajik speakers speak the Sariqul (or Sariköli) dialect and use Uyghur and Chinese to communicate with people of other nationalities in the area. A small proportion of Chinese Tajik speakers speak Wakhi.
A Journey of Geographical and Archarological Exploration in Chinese Turkestan
A Stein - 1904 -
... 15,800 feet above the sea), into Chinese territory on the Taghdumbash Pamir, using
the yaks of the Sarikoli herdsmen...