Iu Mien is Hmong-Mien language spoken by about 840,000 people mainly in China, Laos, Vietnam, Thailand, and also in the USA. Iu Mien speakers are known as Yao - 瑶族 in Chinese, and người Dao in Vietnamese. They are one of the officially recognized ethnic minorities in China, and are also officially recognised as an ethnic group in Vietnam. Iu Mien is closely related to Kim Mun (Lanten), Biao-Jiao Mien, and Dzao Min.
In China the dialect spoken in Changdong in Jinxiu Yao Autonomous County in Guangxi is consider to be the standard. Iu Mien is also spoken in in Guangdong, Yunnan, Hunan and Guizhou provinces.
Iu Mien was written with Chinese characters in China for several centuries, then a Romanized script was devised for the language by Western linguists in the 1930s. The Iu Mien Unified Script, based on the Romanized script used in China, was created at a literacy conference in Guangdong province in 1984 by delegates from the USA, China, and Thailand.
The tone letters appear at the ends of words and are used to indicate the different tones of Iu Mien.
Information about Iu Mien pronunciation compiled by Wolfram Siegel
Nzangc maac caux aaux qiex nzangc fai goiv qiex nzangc yietc zungv fiev jiex gorn ziangx an jienv naaiv, bun meih aengx longc ganh nyei cong-mengh caux jienv hoqc doqc, hoqc gapv, hnangv gorngv meih njaaux ganh dauh mienh nor yaac fi’hnangv nyei longc meih nyei za’eix caux jienv njaaux, se gorngv maaih norm nzangc fai maaih joux waac haiz oix naaic dangh haaix dauh nor maiv dungx faix hnyouv email bun yie fai heuc yie, mbuo lomh nzoih juangc jienv hoqc mangc gaax, laengz zingh.
Source: http://smithpanh.com/?page_id=15
Books about the Hmong language and people
Information about the Iu Mien language and the Yao people
http://en.wikipedia.org/wiki/Iu_Mien_language
http://smithpanh.com
http://motherteacher.org/mien/meetmienh.html