Tertiary sources compile, summarize, index, or help identify scholarly sources on a topic. They are useful for background research or to get an overview of a topic before delving into secondary or primary sources. Common tertiary sources for modern languages include dictionaries, encyclopedias, handbooks, and other reference sources.
From this page you can
An authoritative guide on the English language, detailing the meaning, history, and usage of 500,000 words and phrases past and present, from across the English-speaking world.
Biographical and critical essays on the lives, works, and careers of influential literary figures.
