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:Moreover, genu as well as splenium thinning may corroborate results from our previous work (Ballmaier et al, 2004c), showing widespread decreases in temporal and parietal gray matter in late-onset depression compared to controls, with prominent decreases in sensorimotor regions.
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