Rather a book to browse through when you need certain info than something to read cover to cover. There's a ton of very condensed information and there's titles galore.
There's also a "other works" section where they mention titles related to the ism discussed, and these can also be from a different time period. So it also shows examples of how a certain ism influenced later movies. Albeit it's not the best way to convey this kind of information.
Also when they mention key figures you don't know if they're directors, writers, actors, etc, so you do have to do extra research for every ism covered. Inconvenient but hey, it's a slim book.
I only recommend this to cinema enthusiasts if you find a bargain price for it, as I did. There's probably other options, with a more clear and organized structure.