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 computational system arising from the ad-hoc computation network point of view has been modeled by combining the notion of distributed data streams [5] with classic distributed approaches to solve problems on particular topologies [6] as the SSSF model [2].
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