Liber Juratus
From Grimoire
Also known as "The Sworn Book of Honorius", the Liber Juratus is a medieval grimoire, compiled by Honorius in the 13th century as the product of a conference of magicians who placed all their knowledge in one volume.
The Liber Juratus contains extensive knowledge on the summoning of demons and the powers therein granted, including magic symbols, incantations, and special instructions as to the ceremonies necessary to gain these powers. All in all, a highly influential, highly dangerous grimoire.
Full text may be found at The Esoteric Archives.