What feature of a book helps to clarify source citations or links?

Footnotes serve as an important feature in a book that clarifies source citations or links. Usually found at the bottom of the page, footnotes provide additional information about a specific statement or reference. This may include citations of sources, elaboration on key points, or references to further reading. By using footnotes, authors can keep the main text clear and concise while still providing readers with the context they need to understand the sources of their information or to explore related topics. This allows for a better understanding of the material and supports academic integrity by properly attributing ideas and research to their original authors.

The other features mentioned, such as the appendix, glossary, and index, serve different purposes. An appendix typically contains supplementary material that aids in comprehending the main text, a glossary provides definitions of specific terms, and an index lists topics or terms found in the book for quick reference. While all these elements contribute to the overall utility of a book, it is the footnotes that specifically address source citations and provide clarity on referenced material.