Although PubMed is the most commonly used biomedical database in the US there are several others that you will want to search. By searching more than PubMed your search, and therefore your research conclusions, will be stronger. PubMed indexes several thousand journals but not the entire corpus of biomedical research, by searching multiple databases you are ensuring you are finding the best information on your topic.
Secondary Biomedical Research Sources
Secondary sources include review articles and other types of resources that summarize primary research materials.
Primary literature includes: articles, theses/dissertations, reports, conferences, and patents and not all of these are found in the typical biomedical databases. Additionally you may need to go to non-biomedical sources depending on your topic and here are listed a few commonly used databases for psychology/psychiatry, education, and science/social sciences/humanities primary literature.
Background information can often be found in medical textbooks. This can be helpful when drafting your search because it will give you the necessary information to understand and appraise articles, find additional keyterms, and write a background section to your research.
At MSU Libraries most major texts can be found, organized by subject, on our Electronic Medical Books guide.
Guidelines & Trials
Other Helpful Links
Grey literature encompasses information sources outside of published, peer-reviewed sources. These include governmental and NGO reports and white papers, association publications, policy briefings, and more. These sources can be extremely helpful depending on your research topic and can add background, nuance, and depth to your understanding and argument.
There are several databases that can search for grey lit and a Google search will work well too. Try multiple avenues to search for these sources.