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 addition, some compatible solutes can serve as efficient protective agents by stabilizing the structures and functions of certain macromolecules (Santoro et al., 1992; Papageorgiou and Murata 1995).
Category: