Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:The results of Pascalis et al. (2005) and Scott and Monesson (2009) are important as they demonstrate that perceptual narrowing of unfamiliar monkey faces can be delayed when provided additional exposure or when infants learn to individuate unfamiliar monkey faces.
Category: