Skiveren, Jette, et al. “The Influence of Needle Size on Pain Perception in Patients Treated With Botulinum Toxin A Injections for Axillary Hyperhidrosis”. Acta Dermato-Venereologica, vol. 91, no. 1, Oct. 2010, pp. 72-74, doi:10.2340/00015555-0991.