Providing citations to the work of others you use to create your paper shows that you are using information ethically and honestly. Citing sources gives credit where credit is due and provides readers with a trail of breadcrumbs, which they may use to learn more about your topic and to follow your line of reasoning. Also, citing your sources shows that you have done the work and respect the intellectual property of the people you cite. Each academic discipline tends to have its own separate citation style, often modeled after the core journals in its field.