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:…including slope of the landscape and distance to road (Fortin et al. 2005), habitat diversity (Boyce, Mao & Merrill 2003), habitat openness (e.g. Creel & Winnie 2005; Proffitt et al. 2009), snowpack and elk density (e.g. Gower et al. 2009; Proffitt et al. 2015), and predation risk from wolves…
Category: