When writing a research essay, the format and references must follow the assigned style such as MLA, APA, or Chicago. APA style requires citations in parentheses in the text and a References list at the end. Information should be cited to avoid plagiarism and copyright details recorded for all sources. APA reference formats include author's last name, publication year for books and author, date, title and URL for websites. The references page is titled "References" and double spaced with the paper title and page number formatted as specified.