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:Care in the succeeding days included analgesia, antibiotics, and high-calorie dietary supplementation as described previously (Chen et al. 1996, 1999, 2014; Chen and Wolpaw 2002).
Category: