Simplify the following text for a Grade 13 native English-speaking person.
Original: Three additional volumes have since been published -- The Necronomicon Spellbook , a book of pathworkings with the 50 names of Marduk ; Dead Names : The Dark History of the Necronomicon , a history of the book itself and of the late 1970s New York occult scene ; and The Gates Of The Necronomicon , instructions on pathworking with the Simon Necronomicon .
Simplified: Simon has written several books about the Necronomicon 's `` discovery '' since its publication in 1974 , such as the popular `` Dead Names : The Dark History of the Necronomicon , '' which is about his life and how he `` discovered '' the book .