Analysis of information sources in references of the Wikipedia article "Trung Á" in Vietnamese language version.
The Appearance of the Arabs in Central Asia under the Umayyads and the establishment of Islam", in History of Civilizations of Central Asia, Vol. IV: The Age of Achievement: AD 750 to the End of the Fifteenth Century, Part One: The Historical, Social and Economic Setting, edited by M. S. Asimov and C. E. Bosworth. Multiple History Series. Paris: Motilal Banarsidass Publ./UNESCO Publishing, 1999. excerpt from page 23: "Central Asia in the early seventh century, was ethnically, still largely an Iranian land whose people used various Middle Iranian languages.
In early Islamic times Persians tended to identify all the lands to the northeast of Khorasan and lying beyond the Oxus with the region of Turan, which in the Šāh-nāma of Ferdowsī is regarded as the land allotted to Ferēdūn's son Tūr. The denizens of Tūrān were held to include the Turks, in the first four centuries of Islam essentially those nomadizing beyond the Jaxartes, and behind them the Chinese (see Kowalski; Minorsky, "Tūrān"). Tūrān thus became both an ethnic and a geographical term, but always containing ambiguities and contradictions, arising from the fact that all through Islamic times the lands immediately beyond the Oxus and along its lower reaches were the homes not of Turks but of Iranian peoples, such as the Sogdians and Khwarezmians.
Russian scholars who used the term 'Middle Asia' synonymously with Turkestan used 'Central Asia' largely to refer to areas outside Russian control, including Afghanistan and 'East Turkestan'.
In early Islamic times Persians tended to identify all the lands to the northeast of Khorasan and lying beyond the Oxus with the region of Turan, which in the Šāh-nāma of Ferdowsī is regarded as the land allotted to Ferēdūn's son Tūr. The denizens of Tūrān were held to include the Turks, in the first four centuries of Islam essentially those nomadizing beyond the Jaxartes, and behind them the Chinese (see Kowalski; Minorsky, "Tūrān"). Tūrān thus became both an ethnic and a geographical term, but always containing ambiguities and contradictions, arising from the fact that all through Islamic times the lands immediately beyond the Oxus and along its lower reaches were the homes not of Turks but of Iranian peoples, such as the Sogdians and Khwarezmians.
