There is no single ancient Egyptian work called The Book of the Dead. Instead, there were collections of "spells" (about 200 altogether) written on papyrus and buried with the deceased to help on the journey to the next life.
No single papyrus contains all the spells. Thanks to many reprints, the most common translation available is by E. A. Wallis Budge; published in 1898. Since then, many other funerary papyri have been translated (and it's also be noted that some of Budge's translation was just plain wrong). Subsequent translations by Thomas George Allen (1968) and Raymond Faulkner (1972, sometimes attributed to Carol Andrews, the editor) are much more up-to-date and contain better supplemental material. The different translations should not be combined.