Style Guides for Government Information:
The Bluebook: A Uniform System of Citation (in-library)
The Complete Guide to Citing Government Information Resources (in-library)
How to Cite US Government Documents in MLA, APA Citation Style (online - Cornell University)
Citing US Government Publications (online - Indiana University)
Tips and Examples from library vendors:
ProQuest Congressional Help - How to Cite (online)
Guidelines from the Government:
Citing Records in the National Archives of the United States (online)
National Library of Medicine (NLM) - Citing Medicine (online)