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:As pathogens, members of this complex are responsible for causing disease on around 100 genera of plants (Farr et al. 1989), and they represent one of the most important group of pathogens associated with opportunistic fungal infections and keratitis in humans (Zhang et al. 2006).
Category: