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:Generation of overlays to compare molecular shape and charge distribution with a known ligand
In addition to property and pharmacophore-based filtering, Screenlamp invokes the ROCS [10] software to generate 3D molecular overlays to evaluate similarity in volumetric and chemistry (or “color” [69]).
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