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:…2011 [10]
Reconstruction of ulna fracture after resection of tumour Reversed lateral upper arm flap with vascularized distal humerus Ulna 1 Good
3 Zhen et al., 2011 [11] Reconstruction of severe tibial shaft fractures Free vascularized fibula or osteocutaneous fibular flap Tibia 38 Good outcome…
Category: