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:In some countries, such as Israel (Lavi and Sussman, 2001), Australia (Kumar, Webber and Perry, 2009), the United States (Strauss and Wohar, 2004), and Malaysia (Goh and Wong, 2010), the empirical evidence generally supports a long-term co-integrating link between labor productivity and
Category: