query: When was the  Brāhmasphuṭasiddhānta written?
passage: Brāhmasphuṭasiddhānta
The Brāhmasphuṭasiddhānta ("Correctly Established Doctrine of Brahma", abbreviated BSS) is the main work of Brahmagupta, written c. 628.[1] Τhis text of mathematical astronomy contains significant mathematical content, including a good understanding of the role of zero, rules for manipulating both negative and positive numbers, a method for computing square roots, methods of solving linear and quadratic equations, and rules for summing series, Brahmagupta's identity, and Brahmagupta’s theorem.
passage: Bhadrakalpikasutra
Bhadrakalpikasūtra (Sanskrit; ) is a Mahayana sutra with 24 chapters written in c. 200-250 CE, said to have been taught by Gautama Buddha in Vaishali. It includes the names of the 1002 Buddhas of this "Fortunate Aeon." The title of this text means the "Fortunate Aeon Sūtra".