•to demonstrate that you have considered other people's opinions and read around your subject; •to acknowledge other people's work and/or ideas - and thus avoid accusations of plagiarism (plagiarism: is the act of presenting the ideas or discoveries of another as one's own); •to provide evidence for a statement; •to illustrate a point or offer support for an argument/idea you want to make; •to enable readers of your work to find the source material, e.g. for a particular methodology you have used; and •to direct readers to further information sources.