When citing sources in a biography, follow a consistent citation style such as MLA, APA, or Chicago. Include in-text citations for direct quotes or paraphrased information, providing the author’s name, publication year, and page number where applicable. Create a bibliography or reference list at the end of the biography, listing all sources consulted in alphabetical order by the author’s last name. Include complete bibliographic information for each source, including the author’s name, title, publication date, and publisher. Be sure to follow the formatting guidelines specified by your chosen citation style.