ISBN 978-90-04-35085-4, doi:10.1163/9789004351134_006. Pellard, Thomas, Proto-Japonic *e and *o in Eastern Old Japanese, Cahiers de Linguistique Asie Orientale
Reconstruction of Proto-Ainu. Leiden: E. J. Brill. 1993. ISBN 90-04-09905-0. Vovin, Alexander. (2000). Did the Xiong-nu speak a Yeniseian language?(页面存档备份,存于互联网档案馆)
Southern China? – Philological and linguistic musings on the possible Urheimat of Proto-Japonic". Journées de CRLAO 2014. June 27–28, 2014. INALCO, Paris.