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:Bayesian (e.g., Brown, Fearn, and Haque 1999; Daniels and Kass 2001) and minimax approaches (Dey and Srinivasan 1985) have been proposed to regularize ̂ by shrinking sample eigenvalues.
Category: