Greetings Sir

I was hoping you could recommend any literature regarding, what you label demon types of entities.
By that I do not mean your garden variety neg or nasty spook. I have significant experience with stardard neg types and even stronger types but almost no experience or real understanding regarding
what is considered real Demon types, a different creature altogether. It is almost impossible to research the topic without huge religious overtones. The term "demon" seems to be hung on any neg type that comes along and I know better than that. I know some can be gleened from various satanic sources but I can not bear the heinous atmosphere/energy surrounding that garbage. I am curious but only at a great distance.
I have always been deeply full of wonder regarding Angels as well, but it seems they keep at an even greater distance and as such even less is known.

Thanks for your time

Dave