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:Benthic foraminiferal assemblage composition is mainly determined by the interplay between organic flux, bottom and pore water oxygenation, and species competition [van der Zwaan et al., 1999; Murray, 2006; Jorissen et al., 2007].
Category: