GSGS series 4228. Second Edition. Italian Istituto Geografico Militare map dated 1911 revised from air photos dated August and September 1943 and January 1944 and reproduced by the N2 Litho. Sec. MMP and P. Coy. SAEC., September 1944. 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.