You must cite correctly. However, to avoid long references on the slides, you can use the short form on the slide and create a slide with references at the end of your presentation that contains the long form.
Example:
On the slide: (Tranfield et al., 2003)
At the end of the presentation: Tranfield, D., Denyer, D. and Smart, P. (2003) Towards a methodology for developing evidence-informed management knowledge by means of systematic review. British Journal of Management, 14, 207-22
