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:Coronary flow rate was adjusted to achieve a mean coronary perfusion pressure of 110 mm Hg in hearts from aortic stenosis rats and 75 mm Hg in hearts from control rats, and was then held constant, achieving comparable myocardial perfusion rates per gram of LV tissue in all groups (8,10).
Category: