Primary, Secondary, or Tertiary
• Primary Literature = Original research/reports published in the biomedical journals (e.g., randomized controlled trials, cohort studies, case reports, meta-analyses, animal studies, etc.)
• Secondary Literature = Indexing and Abstracting Services (e.g., PubMed, International Pharmaceutical Abstracts)
• Tertiary Literature = Summary of the available literature (books, drug compendia, review articles [e.g., Facts and Comparisons, Stat!Ref, Pharmacotherapy: A pathophysiologic approach, etc.])