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:AtVAD1 VASt domain 3D structure modeling and structure-based clustering The 3D structure of AtVAD1 (At1g02120) VASt domain (residues 257 to 449) was predicted with I-TASSER web server (http://zhanglab.ccmb.med.umich.edu/I-TASSER/).
Category: