«Http://www.portaldasaude.pt/Portal/Conteudos/enciclopedia+da+saude//Http://www.nhsdirect.nhs.uk/Languages/leaflets.aspx?Language=pt». Revista Portuguesa de Medicina Geral e Familiar 24, no. 1 (Janeiro 1, 2008): 112. Acedido Abril 16, 2025. https://rpmgf.pt/ojs/index.php/rpmgf/article/view/10474.