Another common citing style that employs the author-date system for in-text citations is the Harvard referencing style. In-text citation: It includes the authors' last name and the year of publication (as well as page numbers if directly cited) in round brackets within the text. For example, (Bourne, 2000, p. 91). Out-of-text citation: The preferred method for citing sources outside of the text is via endnotes. Endnotes are numbered sequentially and included at the end of the paper or manuscript. They provide readers with information about where to find further details on a topic. In addition to the author-date system, the Harvard referencing style also uses a third type of citation called a parenthetical citation. Parenthetical citations are used when a reader might be interested in finding out more about an idea or concept mentioned in the text but doesn't want to read beyond the section heading or figure caption. For example, he or she could be interested in reading more about mental illness but doesn't want to go beyond chapter 5. A parenthetical citation would look like this (chapter 5). Finally, the Harvard referencing style allows for multiple references to be listed under a single category. For example, one could cite both Bourne (2000) and Bourne (2003) under "psychology" because each work covers a different but related topic within the field. Multiple citations of this kind should be separated by commas.