Analysis of information sources in references of the Wikipedia article "Caidar ibne Cavus Alafexim" in Portuguese language version.
During the reign of the caliph Mahdi (158-69/775-85) the Afshin of Oshrusana is mentioned among several Iranian and Turkish rulers of Transoxania and the Central Asian steppes who submitted nominally to him (Iacubi, II, p. 479)