Borges, A. S., M. Rato, A. Brasileiro, C. Fernandes, and A. Rodrigues. “Sexually Transmitted Infections in Men Aged 50 Years and Older in a Sexual Transmitted Diseases Clinic of Lisbon, Portugal”. Journal of the Portuguese Society of Dermatology and Venereology, Vol. 76, no. 3, Oct. 2018, pp. 295-8, doi:10.29021/spdv.76.3.944.