The measure is based on various sources of historical income data.

This is a list of ethnic groups based on national or other sources.

Later data is based on various sources, some otherwise unknown to us.

The story was told in various versions, all based on anonymous sources.

He may instead have based his account on other sources, and even hearsay.

Below table is based on official sources but some data may be missing.

These are based on existing sources of information but presented in a different way.

In fact, most of ancient history is based on single sources.

They were not based on the manuscripts and local sources that his students used to more advantage.

His play is based mostly on poetic and dramatic sources.