How should I cross-reference sources well in an exam?

It can be daunting to have to use sources in an exam situation, as it provides another unknown: as well as not knowing what topic the question will be on, you also don't know what the sources will be. But this can also be an advantage, as even if you don't know the topic that well, you can use information from the sources to help you answer the question. 

As with all exam questions, the first thing is to read the question and the sources carefully. Think about how the sources can be used to answer the question - do they support what it says, or do they oppose it, and how do they do this? You of course also need to think about the origins of the source - who was it written by, when, and with what likely intention?

Another of the key things is to think about how they work together. This is cross-referencing, and a really key A Level skill. You need to compare and contrast the sources to see how they work as a group in answering the question. For example, you might write that sources A and C support the question, as they have similar ideas, but source B is opposed to them and comes from a very different perspective. Or, that while source A discusses x as the main reason, the author of source B suggests it is y, which source C also supports. It can be helpful to talk about the sources in a different order from how they are presented in order to make these connections, so you might talk about source B first, link it to source C, and then talk about source A at the end, or however this works best to make the links between them. 

Then you also need include a conclusion, as with all your exam answers. In this, you should aim to answer the question given. If this is in the form of 'How far do these sources suggest...' then think about to what extent they do suggest this. So this could be: sources B and C both suggest that x was true, but source A does not, so in conclsion, these sources support the idea of x. But if you have cross-referenced successfully throughout the essay, then you will just be summarising your ideas in the conclusion, not making the connections for the first time.