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:Based on current evidence, patients not suitable for the Stupp et al.(1,2) protocol of chemo-radiation to a dose of 60 Gy in 30 fractions include alternative hypofractioned regimes such as 40 Gy in 15 fractions, 45 Gy in 20 fractions and 34 Gy in 10 fractions.
Category: