Pumi, also called Prinmi, is a Sino-Tibetan language spoken in Southwest China. The data proposed for consultation were collected in the prefecture of Muli (Liangshan, Sichuan province). The dialect concerned is that spoken in the township of Shuiluo (水洛乡); it belongs to the Northern dialect group.
About the tone system of this dialect:
Jacques, Guillaume. 2011. "Tonal alternations in the Pumi verbal system." Language and Linguistics 12 (2): 359-392. (in pdf here)
About various Pumi dialects:
Ding, Picus Sizhi. 2006. "A Typological Study of Tonal Systems of Japanese and Prinmi: Towards a Definition of Pitch-accent Languages." Journal of Universal Language 7: 1-35.
Matisoff, James A. 1997. "Dayang Pumi phonology and adumbrations of comparative Qiangic." Mon-Khmer Studies 27: 171-213.
Michaud, Alexis, and Guillaume Jacques. 2010. "Insights into Naxi and Pumi at the end of the 19th century: evidence on sound changes from the word lists by Charles-Eudes Bonin." Cahiers de Linguistique - Asie Orientale 39 (1): 21-40. (in pdf here)
Lu Shaozun. 1983. Pumiyu Jianzhi 普米语简志 [A Presentation of the Pumi Language]. Beijing: Minzu Chubanshe.