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:For the implementation we worked with the existing German ParGram grammar (Dipper, 2003), which already contained a syntactic treatment of German discourse particles.7 The German grammar also already contained a basic semantic AKR component (Bobrow et al., 2007).
Category: