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:SVM and MaxEnt have proved successful in information structure analysis (e.g. (Merity et al., 2009; Guo et al., 2011)) but, to the best of our knowledge, their semi-supervised versions have not been used for AZ of full articles.
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