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:These include four reports on the survival of Jewish women with BRCA1/2 mutations diagnosed with EOC.(8,10,11,13) It has been postulated that this improved outcome may be the result of increased platinum sensitivity in BRCApositive tumors.
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