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:…has been undertaken at several locations including the Ganges delta of southern Bangladesh (Wang and Imhoff 1993), Everglades National Park (Simard et al. 2006), Madagascar (Pasqualini et al. 1999), Kakadu and Daintree National Parks in Australia, French Guiana and Malaysia (Lucas et al. 2007).
Category: