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2. Shifting cultivation in Vietnam: Its social, economic and environmental values relative to alternative land use, Do Dinh Sam, 1994, IIED Forestry and land use series No.3.
3. Hmong-Mien language history;Ratliff,2010
4. Indigenous peoples, poverty, and development;Hall,2012
5. Hmong Refugees in the New World: Culture, Community and Opportunity, Christopher Thao Vang, 2016.