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:We demonstrate that a spatial registration strategy of pooling all data disregarding disease status or scanner (study site and/or MFS) produces results with the greatest validity in terms of biological plausibility (Frisoni et al., 2010).
Category: