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:The result is consistent with the suggestion by Furuya et al. (1994; 2000) that the contribution of the Rydberg states to CH+3 is comparable to that of the (1t2)
 ‚àí1 state.
Category: