What Necronomicon do you speak of? The one by Simon?
How many versions are there? I know of the Simon, Tyson and the Nec Spellbook which I believe has a few following titles. I remember hearing of one relating to the Atlantean current but can’t remember where I read it.
So can the creature from Alien.
I worked with the Necro, mainly Marduk. The system is damn powerful.
I own most of them, but have never worked with any. But if you plan on doing so, then I would say go for the books by Simon; they are the most worked with and you can find a lot of in depth info on them from various “Gatewalkers”. Tyson’s books are fairly new and wholly based on Lovecraft, and the books by Joshua Free are scatter brained. Also look into Asenath Mason, she wrote two good books on the subject and is great at returning emailed questions on any subject she works with.
S. Ben Qayin wrote a grimoire of evoking the Nec entities as well, I can’t remember the name at the moment but a google search should bring it up.
the simon necronomicon not only works but is very powerful and has some heavy science behind it. give it a try if you want it works really well