scholars.

A periodical index is a tool that helps users to find articles and other types of information that have been published in periodicals, such as magazines, journals, and newspapers. Periodical indexes can be either print or digital and may include a wide range of periodicals or be focused on a specific subject or type of periodical.

The history of periodical indexes dates back to the 19th century when the first index to a specific periodical was published. The first general periodical index, The Reader’s Guide to Periodical Literature, was published in 1890 and indexed articles from a wide range of magazines. Since then, periodical indexes have become an important tool for researchers, scholars, and other users who need to find information published in periodicals.

There are several types of periodical indexes, including:

1. General periodical indexes: These indexes cover a wide range of periodicals and may include articles on a variety of subjects.
2. Subject-specific periodical indexes: These indexes focus on a specific subject or field of study and include articles from periodicals that are relevant to that subject.
3. Citation indexes: These indexes provide information about articles that have been cited in other works, and can be used to track the impact of a particular article or to find related works.

Periodical indexes are used to find articles and other types of information published in periodicals. They are an important tool for researchers, scholars, and other users who need to find and access this type of information.