Gordon Lauren, Paul (1978). "Human Rights in History: Diplomacy and Racial Equality at the Paris Peace Conference". Diplomatic History. 2 (3): 257–278. doi:10.1111/j.1467-7709.1978.tb00435.x. S2CID154765654.
The Red Seal permit was re-discovered in 1985 by Professor Hayashi Nozomu, in the Bodleian Library. Massarella, Derek; Tytler Izumi K. (1990) "The Japonian Charters" Monumenta Nipponica, Vol. 45, No. 2, pp 189–205.
J. Bartlet Brebner, "Canada, the Anglo-Japanese alliance and the Washington conference." Political Science Quarterly 50.1 (1935): 45-58. online
David Wen-wei Chang, "The Western Powers and Japan's Aggression in China: The League of Nations and" The Lytton Report"." American Journal of Chinese Studies (2003): 43–63. online
Gordon Lauren, Paul (1978). "Human Rights in History: Diplomacy and Racial Equality at the Paris Peace Conference". Diplomatic History. 2 (3): 257–278. doi:10.1111/j.1467-7709.1978.tb00435.x. S2CID154765654.