The Thai version of the "treaty between Thailand and Japan concerning the continuance of friendly relations and the mutual respect of each other's territorial integrity", concluded in Tokyo on 12 June 1940 <a href="https://en.wikipedia.org/wiki/Common_Era" class="extiw" title="w:Common Era">CE</a>, together with the royal proclamation of King Rama VIII dated 23 December 1940 <a href="https://en.wikipedia.org/wiki/Common_Era" class="extiw" title="w:Common Era">CE</a> promulgating the said treaty, as published in the Thai Government Gazette on 24 December 1940 <a href="https://en.wikipedia.org/wiki/Common_Era" class="extiw" title="w:Common Era">CE</a>.
Government of Thailand
1940-12-24
<a rel="nofollow" class="external text" href="http://www.ratchakitcha.soc.go.th/DATA/PDF/2483/A/944.PDF">Royal Thai Government Gazette, volume 57, issue 0 A, dated 24 December 1940, pp. 944–949</a>