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:The main absorptive organ in the cephalopod has long been considered to be the cecum [4], and the large cecal sac and intestine are thought to be the main organs of absorption in the Loliginidae [1, 2].
Category: