Both Catholics and Protestants considered the Malleus Maleficarum (also known as Hammer of Witches) by Heinrich Kramer and Jacob Sprenger as an authoritative work on witchcraft.
This 1487-book it is considered by many as the most famous work of witchcraft ever written during. The book became an important source for Protestants and Catholics during the "fight" against witchcraft during the Inquisition.