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:…A
Effects of Corn Particle Size and Physical Form of the Diet on the Gastrointestinal Structures of Broiler Chickens
1 - ns: non significant polynomial regression (p > 0.05).
was no influence of the particle size on this variable, contradicting data from Nir et al. (1995) and Nir et al. (1994a).
Category: