There are no books specifically about death witchcraft. That is why I wrote one. However, you can find many texts on death work, necromancy, ancestor work and folklore that can aid your craft. Here are many of the resources that helped me learn.
If you have any more sources, please, please add them. Or you can message me, and I’ll add them. Sources for death witchcraft are elusive, and I would appreciate any extra insight or resource.