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:Consistent with previous work, individual Streptomyces isolates resisted inhibition consistently better than they inhibited others (Davelos et al, 2004a; D’Costa et al, 2006), and on average were resistant to 83% of all other isolates.
Category: