Book: Liber 365 by Aleister CrowleyThe Preliminary Invocation of the Goetia. With the barbarous names of evocation used therein, and the secret rubric of the ritual, by the Master Therion. This is the most potent invocation extant, and was used by the Master Himself in his Attainment. Please note that this ritual is identical with Liber Samekh in many aspects, however, there are differences. This is the 1904 version.
Also try this free pdf e-books:Aleister Crowley - Liber 031
Frater Achad - Liber 31