For most research projects, the process of reviewing the literature and starting to draft your review will be an early activity. Despite this early start, it is usually necessary to continue refining your review throughout your project’s life. The process can be likened to an upward spiral, culminating in the finished product, a written critical literature review of the literature. Once you have a good knowledge of the literature sources available then you could start composing your initial draft of your paper. The literature sources you are likely to make the most use of are often referred to as: