APA reference list example: Presentation slides. The author is listed by last name and initials: Boeninger, C. F. The date is listed by year and month in parentheses, followed by a period: (2008, August). The title of the slides is italicized and is followed by no punctuation: Web 2.0 tools for reference and instructional services The label is listed in brackets, followed by a period: [Presentation slides]. The words “Retrieved from” are followed by the URL, with no period at the end: http://libraryvoice.com/archives/2008/08/04/opal-20-conference-presentation-slides/