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:It has proven a suitable method for determining the content of a CPT curriculum.(14,15,17) The modified Delphi process took place between January and July 2017 and comprised the following: a systematic literature search; selection of a European expert panel; and development of a Web-based questionnaire and its modification in two consecutive rounds followed by a face-to-face meeting and final round.
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