Sheet 94M : Sheet E-47D Chiengrai GSGS 4218 First Edition 1942. Compiled and published originally SGI 1929 and revised to 1941. Published WO 1942. 'GSGS 3919' overprinted '4218' in red. Edition date 1941. Heliographed OSO 1942. 1036/4/42 L.R. Grid IIIB.