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:…H0) between monospecific and mixed patches were assumed when the 95 % confidence intervals did not overlap 100 samples (Badano and Cavieres 2006); when the number of samples was less than 100, we used the extrapolation routine proposed by Colwell et al. (2012) to obtain S0 and H0 to 100 samples.
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