Tham khảo Hình vuông

  1. Mark J. Alves. “Early Sino-Vietnamese Lexical Data and the Relative Chronology of Tonogenesis in Chinese and Vietnamese”. Bulletin of Chinese Linguistics, Volume 11, Issue 1-2, năm 2018, trang 14.
  2. William H. Baxter, Laurent Sagart. Old Chinese: A New Reconstruction. New York, Oxford University Press, năm 2014, trang 151.
  3. Mark J. Alves. “Identifying Early Sino-Vietnamese Vocabulary via Linguistic, Historical, Archaeological, and Ethnological Data”. Bulletin of Chinese Linguistics, Volume 9, Issue 2, năm 2016, trang 273.