R. Kumar, A. Hastir, R. S. Walia, S. Goyal, and A. Kaur, “Prospective randomized study of surgical treatment of pilonidal sinus; primary midline closure after elliptical excision versus rhomboid excision with limberg flap reconstruction versus open excision and healing by secondary intention”, Int Surg J, vol. 4, no. 11, pp. 3646–3651, Oct. 2017.