Dungan is a variety of Chinese spoken in Kyrgyzstan, Kazakhstan and Uzbekistan. There are approximately 50,000 speakers. The native name for the language is Хуэйзў йүян, which means 'language of the Hui'. In Chinese it is known as 东干语 (dōnggānyǔ).
There are two main dialects of Dungan: one with four tones which originates in Shaanxi province in China, and one with three tones, which serves as the standard form of the language and comes from the Chinese province of Gansu. Speakers of Dungan fled from Manchu and Chinese persecution over a hundred years ago after an abortive rebellion.
Dungan was originally written with a version of the Arabic alphabet. Between 1928 and 1953 it was written with the Latin alphabet. Since 1953 it has been written with a version of the Cyrillic alphabet. The method of writing Dungan with the Cyrillic alphabet was devised at a conference on May 27, 1953 in Frunze, Kirghizia.
Information about the Dungan language
Implications of the Soviet Dungan Script for Chinese Language Reform
Glossika Chinese dialects - an introduction to all major varieties of Chinese and to many dialects and sub-dialects: http://www.glossika.com/en/dict/