Handbook of Graphical Models: by Marloes Maathuis, Mathias Drton, Steffen Lauritzen, and Martin Wainwright, eds. Boca Raton, FL: Chapman & Hall/CRC Press, 2018, xviii+536 pp., $140.00(H), ISBN: 978-1-49-878862-5. Issue 531 (2nd July 2020)