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:Although standard economic models based on the idea of utility maximization take more choice to be unambiguously welfare-enhancing, scholars have argued that availability and use of certain products can in reality be detrimental to the society (Crane et al., 2014; Karnani, 2007).
Category: