Jelaskan Imej dari Meriam kereta api dalam bahasa melayu

Hall, D Major.  Military History Journal The South African Military History Society. - Vol 2 No 3 June 1972. Guns in South Africa 1899–1902 Part V and VI

Miller, H. W., Lt. Col. Railway Artillery: A Report on the Characteristics, Scope of Utility, Etc., of Railway Artillery, Volumes I and II Washington: Government Print Office, 1921