 Morris distinguishes four waves of refugees, the second, third and fourth of them coinciding with Israeli military offensives, when Arab Palestinians fled the fighting, were frightened away, or were expelled.A document produced by the Israeli Defence Forces Intelligence Service entitled "The Emigration of the Arabs of Palestine in the Period 1/12/1947 – 1/6/1948" was dated 30 June 1948 and became widely known around 1985.The document details 11 factors which caused the exodus, and lists them "in order of importance"