↑ Nordhoff, Sebastian; Hammarström, Harald; Forkel, Robert; Haspelmath, Martin biên tập (2013). “West Semitic”. Glottolog. Leipzig: Max Planck Institute for Evolutionary Anthropology.
↑ Aaron D. Rubin (2008). “The subgrouping of the Semitic languages”. Language and Linguistics Compass. Blackwell Publishing Ltd. 2 (1): 61–84. doi:10.1111/j.1749-818x.2007.00044.x. P. Haupt (1878) first recognized that the qatala past tense found in West Semitic was an innovation, and that the Akkadian prefixed past tense must be archaic. It was F. Hommel, however, who recognized the implications of this for the subgrouping of Semitic; cf. Hommel(1883: 63, 442; 1892: 92–97; 1926: 75–82).
