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:The development of mathematical models for evolution of primary quantities of interest in bioreactor systems, as well as their incorporation into the design process, have the potential to accelerate the path to realization of optimal functional outcomes in engineered tissues; see [1] for a review of modeling approaches.
Category: