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:We tested following distribution strategies of FF heuristic estimation:
• hFFα using only locally built RPGs (including projections of public actions) and local estimation of FastForward heuristic, as proposed in (Nissim and Brafman 2012).
Category: