Não informado. Puerto Rico Health Bulletin. Insular Department of Health.
Chicago-viite (17. p.)Não informado. Puerto Rico Health Bulletin. San Juan: Insular Department of Health.
MLA-viite (8. p.)Não informado. Puerto Rico Health Bulletin. Insular Department of Health.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.