Tracing Changes Through A Thousand Years — Social Studies STD 7 — Question

Historians use variety of sources to study the past. It depends upon the period of their study and nature of study. They use those resources that provide some continuity. Historians still rely on coins, inscriptions, architecture and textual records.
There appeared some discontinuity as well. The variety of textual records increased from 700 to 1750. They slowly replaced other types of available sources. During this period paper gradually became cheaper and easily available.