The official language of the Mongolia is Mongolian, or монгол, written in Cyrillic. Mongol is an Altaic language, spoken in Mongolia, Russian, Afghanistan, and China. Russian is also used in the country, as well as other languages.
Tajiki textbooks are available at Gelman library through the consortium. While language help is available on Google translate, please note it is limited in its translation capabilites from Mongol-English and English-Mongol.
A large number of sources are available in Russian through Gelman, the consortium, and Gelman online. For historical documents in Russian, you may also search the REECE databases at Gelman.