Four Arthurian Romances - Complete text by de Troyes Crétien from Project Gutenberg. - http://www.gutenberg.org/etext/831
The Court of King Arthur - Complete text by Samuel E. Lowe from Project Gutenberg - http://www.gutenberg.org/etext/6582
Le Mort d'Arthur - Volume 2 - Complete text by Thomas Malory from Project Gutenberg - http://www.gutenberg.org/etext/1252
Le Mort d'Arthur - Volume 1 - Complete text by Thomas Malory from Project Gutenberg. - http://www.gutenberg.org/etext/1251
King Arthur in Literature - Selected list of modern and medieval titles, compiled by Wheaton Public Library. - http://www.wheaton.lib.il.us/library/rlarthur.html
The High History of the Holy Graal - E-text based on the translation by Sebastian Evans (1898) of an anonymous 13th century Old French work. - http://www.sacred-texts.com/neu/graal/