Jump from the Library's overview page to its nice, short itemization of Chicago or MLA.
For example, from here you can find how the Chicago Manual of Style references proper citation to online legal documents and government publications as a primary source in your work (Chicago Manual of Style, 15th ed., sections 17.270, 17.270):
1.Creator’s last name, first name, middle initial (or filmographer’s name if no director is specified, but indicate role).
2.Author’s last name, first name, middle initial (if given).
3.Title of document (subsection is placed in quotes, followed by title in italics).
4.Format (omit if it is a printed page).
5.Publisher city: publishing company, copyright date (include as much information as possible such as page numbers).
6.Source (From Library of Congress in normal font), Collection name with dates (in italics).
7.Medium (software requirement needed to access source).
8.URL (use bibliographic record URL or shorter digital id if available at bottom of bib record).
9.Accessed date (in parenthesis).