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:%) fallow deer were positive to A. phagocytophylum DNA, however a work recently conducted by Michalik et al. (2009) on a population of 44 fallow deer living in West–Central Poland using only a PCR approach, showed a prevalence rate (20.5
Category: