PubMed is a service of the US National Library of Medicine® that: Provides free access to MEDLINE®, the NLM® database of indexed citations and abstracts to medical, nursing, dental, veterinary, health care, and preclinical sciences journal articles. Includes additional selected life sciences journals not in MEDLINE.
Using subject headings to conduct a search is a great way to find relevant information. This short video from National Library of Medicine walks you through the process.
A tutorial from the NCBI describing how to use the Advanced Search to help refine your PubMed searches.