There is some overlap with ...Isms: Understanding Art by Stephen Little. (Tellingly, Phillips claims that the term 'Sensationalism' was "coined for this book", though in fact it first appeared in Little's book.) To avoid duplicating the illustrations from Little's work, Phillips doesn't include iconic paintings such as Les Demoiselles d'Avignon: Cubism, for example, is represented by Gris, instead of Picasso or Braque. This makes the book less useful as an introduction to modern art.
Styles, Schools, & Movements by Amy Dempsey, 100 Artists' Manifestos by Alex Danchev, and Manifesto by Mary Ann Caws all take a similarly 'ismatic' approach to modern art. Dempsey's book, in particular, is a superior guide to modern art 'isms'.