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:Data drawn from Jablensky and Cole (1997). In order of increasing latitude the cities were Cali, Colombia; Ibadan, Nigeria; Agra, India; Honolulu, USA; Chandigarh, India (rural and urban); Nagasaki, Japan; Rochester, USA; Prague, Czech Rep.
Category: