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:In contrast to the results here, Talukdar and Germida (1993) found that AMF colonization was different between lentil and wheat, and Scheublin et al. (2004) found that legumes were colonized by distinctly different AMF communities than nonlegume host plants.
Category: