Cambridge IGCSE™ and O Level History Option B: the 20th Century Coursebook with Digital Access (2 Years) (Cambridge Introduction to World History)

I purchased both Hodder and Cambridge. I feel this Cambridge version is better organized to help students gain a full picture, sub section by sub section. Reading through feels less overwhelming, and I like the timeline summaries to quickly revise the order of events. As an additional bonus, you can access the WWI and WW2 depth studies online through the book's access code.