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:In this sense, oligodendrogliomas can show similar pathological findings to liponeurocytoma [5, 6, 12, 18, 21, 24, 26], although Olig2 immunohistochemistry is reported to show a high possibility of positive results in oligodendroglioma, while neurocytomas are mostly negative [15, 20, 23].
Category: