Works Cited

The Chicago and Turabin styles also use the abbreviated ordinal form -- 2nd ed.

I'll also second Tolley's recommendation. Citationmachine.net works very well for 99.9% of the citations the typical high school or lower division university student might encounter. It is weak, however, when it comes to developing citations for original, unpublished source materials. Your research library may have its own citation generator for the original documents (letters, manuscripts, maps, drawings, notes) in its collection.