Which sources tell us about the Gupta Empire?

There are many inscriptions on stone tablets, clay tablets and gold coins that tell us about the Gupta Age and what happened in those days. There is a pillar in Allahabad that also has inscriptions on information about those days. Coins and literary works also throw light upon the reign of Samudragupta and other rulers of that time. Many foreigners who visited the country at that time had written accounts when they visited the court of the rulers. For e.g., Fa Hien had visited India to study and become a buddhist. He had written an account on his trip to India.