Below are the best books we could find on Dowsing.

Dowsing is a type of divination that uses a forked stick, two L-shaped rods, or a pendulum to locate groundwater, buried metals, oil reserves, utility lines, gemstones, “malign” Earth energies, people, pets, lost items . . . or anything else of value. Dowsers believe that with the proper training and equipment—and intuition—they can sense magnetic fields in the Earth.