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:Recent advanced templatebased approach (17) and new approaches with R2* to HU conversion (41) and zero-echotime (42) show similar results to our approach and/or great potential for further improvement of MR-AC.
Category: