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:Earlier investigations in Cebu Longitudinal Health and Nutrition Survey (CLHNS) samples showed convincing evidence of the role of exposure to a pathogenic environment in predicting plasma CRP levels in Filipinos [9, 10].
Category: