Cambridge IGCSE and O Level History 3rd Edition: Option B: The 20th centuryWe are working with Cambridge Assessment International Education to gain endorsement for this title. Rely on author Ben Walsh's bestselling approach to navigate through the syllabus content and help students acquire the skills they need. The book covers all the Key Questions and Focus Points for Core Content Option B 'The 20th century: International Relations since 1919' and selected depth studies: Germany, 1918 45; Russia, 1905 41; The USA, 1919 41.