The Decree No. 4702-CP on December 21, 1933 of Nam Ky (Southern part) Governor Krautheimer on merging the Truong Sa, An Bang, Itu Aba archipelagoes and the group of Song Tu Đông and Song Tu Tay, Loai Ta, Thi Tu islands and other dependent islands with Ba Ria province (Source: Bulletin Administratif de Cochinchine, No. 1, 1934).