Links to Papal EncyclicalsEncyclicals
Vatican Homepage - You should be able to find any document you need here.
Papal Encyclicals Online - an extensive list of Papal Encyclicals including some Popes back to the 12th century.
RCnet - List of Papal Encyclicals. Many are from the 1800's and some from before then.
St.Gabriel's Bookstore If you need to buy the print version look here.