Jyotihshastra: Astral and Mathematical Literature c4.s4.3

c4.s4.3

In fact, the earliest such *koṣṭhaka* concerning which we have any information is apparently the *zīj* composed by Durlabha¹⁷² at Multān in Sind; its epoch is 932. Our only source of knowledge of this *zīj*, however, is al-Bīrūnī's India; and he quotes from the instructions rather than the tables, which presumably accompanied those instructions if the work was indeed a *zīj*.