Whether you choose to quote or paraphrase sources you use in your research paper, you must cite each one. For rules and examples of the MLA citation style, look here:
Sometimes students will use online citation formatters provided free on the Web or within a library database. If you use one of these online formatters, remember that they are not foolproof. You will need to review your citations to make sure they are correct.
It is important to do some critical evaluation to decide whether the sources you find, particularly online sources of information, are appropriate and usable for your University research assignment. When you are evaluating a website, the methods linked from Evaluating Internet Resources provide useful guidance in determining the source, scope, currency, accuracy and bias of a site.
Remember that you must properly credit information taken from the Web when used for research purposes, even if the material is considered to be in the public domain.