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:For controls, all three primer pairs were tested in the second-round PCR. Primers specific to Botrytis, Cladosporium and Fusarium (Table 1) were designed based on the
ITS sequences from our previous publication (Shipunov et al., 2008).
Category: