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:quantification of RAM in the biological fluids including liquid chromatography-tandem mass spectrometry (LC-MS/MS) (Gupta et al., 2011; Pilli et al., 2011; Patel et al., 2014), high performance
Category: