Here are a couple of online guides that specifically address citing government documents:
Indiana University Guide: Citing U.S. Government Publications:
Clear examples for citing specific types of government publications in a variety of formats. It does not address citing according to specific style guides.
Naval Postgraduate School: Dudley Knox Library. Citing Styles
Specific examples for citing government publications according to APA and Chicago style guides. Click on the link for your preferred style then navigate to the specific type of government publication.