The main things I have noticed while I did the past papers is that a good part of the sources depict someone being blamed, for example in the Manchurian Crisis, the author or cartoonist might blame either Britain or France, or even the USA. They might also attack the Japanese for being warmongering and stuff. You should try the following past papers.May/June 2012October/November 2016To my knowledge, these years had the League of Nations as their topic.