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:…some extensions of the above factorization methods are proposed, including the TrAnsfer Learning for MUltiple Domains (TALMUD) (Moreno et al., 2012), the extended Cluster-level Latent Factor Model (CLFM) (GAO ET AL., 2013B;A) and the Cross-Domain Triadic Factorization (CDTF) (Hu et al., 2013).
Category: