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:However, earliest observations of cutaneous horns in humans were described by British surgeon Everard Home in 1791.[4] Farris from Italy first described the gigantic horn in man as well as documented a case report with adequate histology.
Category: