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:Parallelization with GNU parallel
 To get the subset of results related to the e-commerce packages of interest, we merged the top 40 list provided by Robertshaw, the top ten of builtwith.comand the leading systemsfrom the Gartner and Forresterreports, as already mentioned.
Category: