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:This scenario corresponds to the structure of irreversible MichaelisMenten, well-known in the literature (Heinrich and Schuster, 1996), where an enzyme appears predominantly in the reversibly interconvertible forms of the free enzyme E and the enzymesubstrate complex ES, and the product P is irreversibly produced from the enzyme-substrate complex.
Category: