Excerpts from Books and Wikipedia
"Still, the visit of the Hindu delegation to the Abbasid court, around 771, marked a true turning point in Arab intellectual history. The Indian sages brought with them prized Sanskrit scientific texts, believed to be in part the work of the seventh-century scholar Brahmagupta and known as the siddhanta." [Lyons: House of Wisdom, p. 71] "Brahmagupta (…) was an Indian mathematician and astronomer. . . . Brahmagupta was the first to give rules to compute with zero. The texts composed by Brahmagupta were composed in elliptical verse in Sanskrit, as was common practice in Indian mathematics. As no proofs are given, it is not known how Brahmagupta's results were derived." [Wikipedia]