^Schuessler, Axel (2014) "Phonological Notes on Hàn Period Transcriptions of Foreign Names and Words" in Studies in Chinese and Sino-Tibetan Linguistics: Dialect, Phonology, Transcription and Text. Series: Language and Linguistics Monograph. Issue 53. p. 257 of 249-292
^Pulleyblank, Edwin G. (1983). "The Chinese and Their Neighbors in Prehistoric and Early Historic China," in The Origins of Chinese Civilization, University of California Press, p. 452 of pp. 411–466.