PubMed is the preferred database by many doctors, nurses, and other medical personnel. Not all resources listed are available in full-text, but each article does include a short description including a summary of the outcome of the medical research (clinical trials, case studies, etc.). PubMed® comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.