原始日语ISBN 978-1-61451-161-8, doi:10.1515/9781614511151.13, (原始内容存档于2021-01-01). Serafim, Leon A., The uses of Ryukyuan in understanding Japanese language history
原乡 (语言学)Archaeology, Linguistics and Genetics. London/New York: Routledge-Curzon. Serafim, Leon A. The uses of Ryukyuan in understanding Japanese language history.