AMA (American Medical Association) Style
This site gives a general overview and examples of major publication types. It is maintained by New York Medical College Library.
AMA Manual of Style
This is the full-text of the 10th edition with extensive search and browse options, policy updates made in real time, an SI conversion calculator, learning and training resources, and monthly commentary.
Citation Styles Handbook-APA Format
This site gives examples for citing books, journals, Internet resources, and other sources. It is maintained at the University of Illinois.
Online: A Reference Guide to Using Internet Resources, Citation Styles
This site describes electronic and Internet formats for four major publication styles. The site is maintained by Bedford St. Martin's, a publisher of college materials
International Committee of Medical Journal Editors
Includes Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly work in Medical Journals.