Reference materials
Providing background information. These sources answer who, what, where, when and why questions and are more useful for purposes of identification than for in-depth research
Books
Providing in-depth and/or historical analysis of a subject
Journal Articles
Written by experts in the field. Journal articles are typically published after undergoing a peer-review process. Peer review involves the assessment of the validity, quality, and originality of articles by experts in the same field. These articles present original research data and findings or express a position on a significant question within the field.
Databases
Collection of one or more types of materials mentioned above.