Manual of The Mother Church

The Church Manual of The First Church of Christ, Scientist, in Boston, Massachusetts, commonly known as the Manual of The Mother Church, is the book that establishes the structure and governance of The First Church of Christ, Scientist, also known as The Mother Church, functioning like a constitution. It was written by Mary Baker Eddy, founder of the church.

Source: Wikipedia — Manual of The Mother Church (CC BY-SA 4.0)