The 'goethia' is a list of numbered (Christian, as in rulers of hell) demons of which their benefits are documented (this one only speaks the truth in a magical circle, this one provides great riches, etc) and their position as a (smaller) lord of hell, e.g. A Grand Duke of hell, commanding 16 legions of demons.
I've seen these demons used in some derived works, such as Shin Megami Tensei ('true goddess reincarnation', the title is meaningless, but the series very much covers demonic pacts in the modern age) or some random internet fiction (one that covers the freemasons essentially regulating demon summoning and fighting against a 'rogue' summoner that has somehow freed a major demon. Mighty demons from the goethia are send to drag him to hell)
The descriptions are consistent, which suggests a common source (also, almost all demons from the Shin Megami Tensei are literally real myths or based on them. This is not hidden, Lucifer and YHWH occur in most games in the series (although their motives are ... interesting))
However, what even is the Goethia? Is this an old occult manual? Some tale or collection of tales? Does it have anything to do with Goethe? (Perhaps the tale of Faust and the demon summoned by the name of Mephistofeles?)
So, what sort of mythological artifact is this 'goethia' and where can I find an authoritative source on it?