Gupta, R., P. Lavania, V. K. Bansal, N. Agarwal, and A. Singh. “Cutaneous Horn Developing over a Verrucous Carcinoma: A Rare Entity With an Unusual Presentation”. International Surgery Journal, vol. 3, no. 2, Dec. 2016, pp. 988-90, doi:10.18203/2349-2902.isj20161185.