GSGS (Series); 2871. 3rd ed., Army/Air Style. Includes inset of Socotra and neighbouring islands. "Projection of the International Map." "Drawn and heliographed by O.S. 1942."
GSGS (Series); 2871. 3rd ed., Army/Air Style. "Projection of the International Map." "Copied from a map by the Trigonometrical Survey Office, Pretoria, dated 1941. Photolithographed by O.S. 1943."
GSGS (Series); 2871. 3rd ed., Army/Air Style. "Projection of the International Map." "Copied from a map by the Union of South Africa dated 1940. Heliographed by O.S. 1942"