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, these general network properties were demonstrated to have great impacts on the networkbased problems, such as traffic transport [12, 13, 14, 15, 16], epidemic spreading [17, 18, 19, 20, 21], network attacks [22, 23, 24, 25, 26, 27, 28], synchronization [29, 30] and control [31, 32, 33, 34, 35, 36], link prediction [37, 38, 39], etc.
Category: