Analysis of information sources in references of the Wikipedia article "Мухаммед ибн Баис" in Russian language version.
«According to one of al-Tabari’s authorities (iii, 1388), the shaykhs of Maragha who praised the bravery and literary ability (adab) of Ibn Bai’th also quoted his Persian verses (bi’l-fdrisiyya). This important passage, already quoted by Barthold, BSOS, ii (1923), 836-8, is evidence of the existence of the cultivation of poetry in Persian in northwestern Persia at the beginning of the 9th century. Ibn Bai’th must have been Iranicised to a considerable extent, and, as has been mentioned, he relied for support on the non-Arab elements in his Rustakhs (‘Uludj Rasatikhi’)»
