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:, 1984a,b; Laughon and Scott, 1984), a peptide motif conferring sequence-specific DNA binding ability to the homeoproteins (Laughon and Scott, 1984; Desplan et al., 1985; Beachy et al., 1988; Müller et al., 1988; Ekker et al., 1991).
Category: