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:…solutions with the algorithms from Abramov (1989), Petkovšek (1992), Abramov and Petkovšek (1994), Abramov and Zima (1996), Bronstein (2000), Schneider (2001, 2005c), simplifying the solutions by our advanced telescoping algorithms (Schneider, 2005a, 2008, 2010c, 2015) and taking the first…
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