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:Following Gunz and Mitteroecker (2013), a semi-automatic point placement strategy was used to place surface sliding semi-landmarks on the digitized bone surfaces, as implemented in the ‚ÄòplacePatch‚Äô function (Schlager 2016).
Category: