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:Similar results were demonstrated for the identification of Haemophilus somnus from naturally infected bovine lungs (Tegtmeier et al., 2000), which emphasises the need of alternative detection methods to complement the culture based at establishing a definitive diagnosis.
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