Wang & Chen (1981) covers the dialect of Pengpan 碰拚, Dafengshan Township 大凤山乡,Shuangjiang County.
Zhou & Yan (1983) covers the dialect of Pangpin 胖品,[3] Yongge Township 永革乡,Shuangjiang County.
Yan & Zhou (2012) cover U of Gantang 甘塘,[4][5]Yongde County as well as U of Pangpin 胖品.
Svantesson (1991:67) documents the U dialect of Pã Xɛp (Bangxie, 邦协), Shahe Township 沙河乡,Shuangjiang County.[6]
There two main dialects of U inShuangjiang County: one spoken in Gongnong (公弄, now part of Mengku Town, 勐库镇) and one spoken in Bangbing (邦丙) and Dawen Mangga (大文乡忙嘎); the Dawen dialect is reportedly mutually intelligible with that ofShidian County (Shuangjiang County Ethnic Gazetteer 1995:160).
Avala (autonym:a21 va21 la21) is spoken in Bangliu (邦六),[7] Manghuai Township (芒怀乡), Yun County (云县), Yunnan, China.[8][9]
Simao Xingshu Minzu Shiwu Weiyuanhui Bian 思茂行署民族事务委员会编 (1991).Bùlǎngzú yánjiū布朗族研究 [A Study of the Bulang People] (in Chinese). Kunming: Yunnan renmin chubanshe.ISBN7-222-00803-9.
Svantesson, Jan-Olof (1988)."U"(PDF).Linguistics of the Tibeto-Burman Area.11 (1):64–133.Archived(PDF) from the original on 2014-02-23. Retrieved2012-06-02.
Tao, Chengmei 陶成美 (2016).Bùlǎngyǔ duōxiàng dìngyǔ jí qí yǔxù yánjiū布朗语多项定语及其语序研究 (M.A. thesis) (in Chinese).Zhongyang Minzu Daxue.
Tao, Yuming 陶玉明 (2012).Zhōngguó Bùlǎngzú中国布朗族 [The Bulang People of China] (in Chinese). Yinchuan: Ningxia renmin chubanshe.
Wang, Xingzhong 王兴中; Zhao, Weihua 赵卫华 (2013).Líncāng dìlǐ yǔ shuāngyǔ shǐyòng临沧地理与双语使用 [Geography and Multilingualism in Lincang] (in Chinese). Kunming: Yunnan renmin chubanshe.ISBN978-7-222-08581-7.
Yan, Qixiang 颜其香; Zhou, Zhizhi 周植志 (2012).Zhōngguó Mèng-Gāomián yǔzú yǔyán yǔ Nányǎ yǔxì中国孟高棉语族语言与南亚语系 [Mon-Khmer Languages of China and the Austroasiatic Family] (in Chinese). Beijing: Shehui kexue wenxian chubanshe.
Gazetteers and other Chinese government sources with lexical data
Nanjian County Gazetteer Commission [南涧县志编纂委员会编] (ed). 1993.Nanjian County Gazetteer [南涧彝族自治县志]. Chengdu: Sichuan Reference Press [四川辞书出版社].
Na Ruzhen [納汝珍], et al. (eds). 1994.Zhenkang County Ethnic Gazetteer [镇康县民族志]. Kunming: Yunnan People's Press [云南民族出版社].
Simao Prefecture Ethnic Minority Affairs Bureau [思茅行暑民族事务委员会] (ed). 1990.A study of the Bulang people [布朗族研究]. m.s.
Xiao Dehua [萧德虎], et al. (eds). 1992.Zhenkang County Gazetteer [镇康县志]. 1992. Chengdu: Sichuan People's Press [四川民族出版社].