What’s difficult about looking into Witchcraft is Wicca is bled into it so much. I know they’re separate things, but it’s just so hard to find Witchcraft on its own.
I think the problem may be that what you’re looking for doesn’t exist is quite the way you’re looking for it. Witchcraft isn’t a single thing but a term that can be used to describe a variety of beliefs and practices in a number of different cultures. So when you look for witchcraft, the question becomes - what kind? what culture? what era? Wicca is a modern take on it and heavily influences most modern books on the subject.
A solution can be to go back and begin researching original sources. But when you do this, you generally won’t find a coherent set of practices that can fit in to modern society. You will find reconstructionist groups trying to reinterpret and rebuild around older practices and if a particular type calls to you, you can look into it.
Sacred-texts.com is a good source for things like the Greek Magical Papyri and Hermes. Lately I’ve been making my way through http://avaloniabooks.co.uk/ They have a Wiccan section but you’ll find things like the Cunningman’s Handbook and the Grimoire of Pope Honorius. I haven’t made my way to this yet, but the book on Thracian Magic is a good example of how difficult it can be to adopt ancient traditions to modern times. I’m unlikely to try to ensure the health of a pregnant mother and her baby by drowning a black puppy. But that was once a part of folk healing in the area.
Or you could study Ceremonial Magic and Qabalah, which can be very complex. There’s also Santaria and Voodoo traditions, though really it’s best to leave those to be practices within the culture because otherwise there can be complications involving gods and expectations.
Hopefully some of these sources will help. Sacred-texts is free. So is Project Gutenberg. Some Avalonia titles are available as Kindle ebooks and even in the Kindle library for free if you have Amazon Prime.