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:According with our previous results (Orihuela & Croxatto 2001, Orihuela et al. 2001, 2003) and those shown in this paper we propose a model indicating that the nongenomic pathway utilised by E2 to accelerate oviductal transport of oocytes in cycling rats involves successive activation of the…
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