Pseudomonarchia Daemonum
The most obvious source for the "Ars Goetia" is Johann Weyer's "Pseudomonarchia Daemonum" in his "De praestigiis daemonum". Weyer does not cite, and is unaware of, any other books in the "Lemegeton", suggesting that the "Lemegeton" was derived from his work, not the other way around. The order of the spirits changed between the two, four additional spirits were added to the later work, and one spirit (Pruflas) was omitted. The omission of Pruflas, a mistake that also occurs in an edition of "Pseudomonarchia Daemonum" cited in Reginald Scot's "The Discoverie of Witchcraft", indicates that the "Ars Goetia" could not have been compiled before 1570. Indeed, it appears that the "Ars Goetia" is more dependent upon Scot's translation of Weyer than on Weyer's work in itself. Additionally, some material came from Heinrich Cornelius Agrippa's "Three Books of Occult Philosophy", the "Heptameron" by pseudo-Pietro d'Abano, and the "Magical Calendar".