Hi Tushar,

The problem in finding literary sources is the fragility of the medium that was there. They used palm-leaves inscribed with a stylus and rubbed with ink. In the hot climate of India palm leaves quickly deteriorate and are subject to be damaged by insects. The other problem is cows and other animals getting into one’s library and eating one’s manuscripts.

The Vedas and other important literature was never written down on a hard paper but memorized and transmitted orally for thousands of years.

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!