Additionally, a number of scholars have proposed that the Mahāyāna Prajñāpāramitā teachings were first developed by the Caitika subsect of the Mahāsāṃghikas. They believe that the "Aṣṭasāhasrikā Prajñāpāramitā Sūtra" originated amongst the southern Mahāsāṃghika schools of the Āndhra region, along the Kṛṣṇa River. These Mahāsāṃghikas had two famous monasteries near Amarāvati and the Dhānyakataka, which gave their names to the Pūrvaśaila and Aparaśaila schools. Each of these schools had a copy of the "Aṣṭasāhasrikā Prajñāpāramitā Sūtra" in Prakrit. Guang Xing also assesses the view of the Buddha given in the "Aṣṭasāhasrikā Prajñāpāramitā Sūtra" as being that of the Mahāsāṃghikas. Edward Conze estimates that this sūtra originated around 100 BCE.