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:Minimizing the first two terms of equation 6.7, which are
7 This mechanism was proposed in Amari (1977) and Pouget and Zhang (1997).
of order 1, determines that the stable state is on the line attractor.
Category: