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:First, the entrance of sodium during cell depolarization mediated by glutamate may trigger multiple events potentially leading to cell death, such as the influx of chloride and water (causing cell swelling), a sodium-induced increase in cytosolic calcium, or a decrease in intracellular pH (28, 29).
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