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 the domain of supply chain, logistics, and operations management, the approach has been popularized by Holmström et al. (2009),
leading to promising initial applications (e.g., Finne and Holmström, 2013; Schleper and Busse, 2013; Tanskanen et al., 2015).
Category: