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:Among the most successful are Spectral Sequencing [62], Optimally Oriented Decomposition Tree [6], Multilevel based [68], Simulated Annealing [79, 78], Genetic Hillclimbing [81] and some of their combinations.
Category: