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:Lennard-Jones interactions were evaluated using a straight 1.2 nm cutoff for Gromos53A6, Gromos54A7, and Berger and a 1.0 nm cutoff for OPLS.
Category: