GSGS series 4228. Second Edition. Italian Istituto Geografico Militare map dated 1935 and revised from Air Photographs dated Sept 1943 and Apr. 1944. Revised by 7 Gen. Fd. Svy. Sec. R.E. Nov. 1944. Reproduced by 518 Corps Fd. SVy. Coy. R.E. Nov. 44. The meridians are based on the meridian of Rome, which is 12 degrees, 27 minutes and 7.1 seconds east of Greenwich. North Italy Grid.