Do not list a reference that you have not seen 1
Cite only directly pertinent references.2
Identify methods, procedures and equipment in sufficient detail to allow for reproducibility of results. For specific equipment, give the manufacturer's name and address in parentheses.2
Provide references and brief descriptions for methods that have been published but are not well-known. Give reasons for using them and evaluate their limitations.2
1. Patrias K, author; Wendling D, editor. Citing Medicine: The NLM Style Guide for Authors, Editors, and Publishers [Internet]. 2nd edition. Bethesda (MD): National Library of Medicine (US); 2007 [cited 2018 May 10]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK7256/
2. International Committee of Medical Journal Editors (ICMJE) . Recommendations for the Conduct, Reporting, Editing and Publication of Scholarly Work in Medical Journals [Internet]. ICMJE. Updated December 2017 [cited 2018 May 10]. Available from: http://www.icmje.org/recommendations/.
The ICMJE Recommendations does not offer advice on how to cite within a PowerPoint, however one can assume that like an article this format needs citations.
Examples are forthcoming.