D. H. Jones, M. Kerscher, T. Geister, M. A. Hast, and P. Weissenberger, “Efficacy of IncobotulinumtoxinA for the Treatment of Glabellar Frown Lines in Male Subjects: Post-Hoc Analyses from Randomized. Double-Blind Pivotal Studies”, J of Skin, vol. 1, no. 3.1, p. s70, Oct. 2017.