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The source library.

Explore early cities, languages, religion, Kabbalah, alchemy, philosophy, human origins, and disputed history. Open a guide, follow its sources, and keep the next question in view.

This collection contains published introductions to the growing knowledge base. Each guide links its sources; traditions and open hypotheses retain their context.

1 of 96 source guides

South Asia 499 CE (traditional scholarly date)

The Āryabhaṭīya: dating a work and its witnesses.

The Āryabhaṭīya is traditionally dated to 499 CE. See how its critical edition lets the research record keep the composition, the author, and each surviving manuscript as separate objects.