Name Info Provider Link
free resource BioMed Central https://bmcpublichealth.biomedcentral.com/articles/10.1186/1471-2458-9-249
Clinical Trials free resource MedlinePlus Health Information https://medlineplus.gov/clinicaltrials.html
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/19619283/
free resource Europe PubMed Central https://europepmc.org/abstract/MED/19619283