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Its administrative area corresponds to roughly the modern provinces of central and southern Shaanxi, southern Ningxia, eastern Gansu, western Henan and southwestern Shanxi.
References
Shi Weile, ed. (2005). Zhongguo Lishi Diming Da Cidian (中国历史地名大词典) [Large Dictionary of Chinese Historical Place Names] (in Chinese). China Social Sciences Press. p. 1728. ISBN7-5004-4929-1.