Grey Literature is high quality information produced on all levels of government, academia, business, industry, and independent science and health organizations. (It is not controlled by commerical publishers.) For the full list: GreyLiterature tab on the Nursing and Health Studies Guide
CDC (Center for Disease Control and Prevention CDC is part of Department of Health and Human Services. To find information, use the Search box, A-Z Index button, and on the horizontal banner, the Diseases and Conditions or More tabs.
PLOS (Public Library of Science) PLOS is an nonprofit Open Access science organization that publishes the world's largest multidisciplinary peer-reviewed journal.
BioMedCentral To find the Search button, go the far right corner of the blue banner, top of the page.
TRIP TRIP is a search engine finding finding international high quality research evidence.
PubMed - health sciences and biomedical database from the National Library of Medicine
Web of Science - includes several subjects including biology, medicine, biomed., chemistry, etc.
CINAHL - excellent for health studies and many health disciplines.
Embase - biomedical, sciences, and drug related information
Proquest Research Library - good place to start or go to if the information is not available or is too specific in previous databases.