American Psychological Association (APA) Style
- APA Style Online - general information about the Publication Manual of the APA
- Electronic References - excerpts from the Publication Manual of the APA
- APA Citation Guide (Ohio State University) - downloadable PDF guide
- APA Citation Style (Long Island University) - color-coded examples based on Publication Manual of the APA
- APA Documentation (University of Wisconsin-Madison) - links to specific formatting issues
- APA Formatting and Style Guide (OWL at Purdue University) - site includes guidelines for all aspects of writing
- Citation Machine (The Landmark Project) - free citation formatting
- Guide to Citation Generators (University at Albany Libraries)
- Interpreting Citations Tutorial (University of Missouri-St. Louis)
The National Library of Medicine Style
- Citing Medicine - The NLM Style Guide for Authors, Editors, and Publishers (2nd Edition 2007)