Não informado. Puerto Rico Health Bulletin. Insular Department of Health.
Chicago-referens (17:e uppl.)Não informado. Puerto Rico Health Bulletin. San Juan: Insular Department of Health.
MLA-referens (8:e uppl.)Não informado. Puerto Rico Health Bulletin. Insular Department of Health.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.