An interesting site to clarify doubts whilst writing papers.
From their About Us: “Grammarist is cooperatively written and edited by a group of U.S.-based writers. We are anonymous (for now), because we prefer to keep this labor of love separate from our professional lives. Most of what we write here is based on our own research and experience. When in doubt, we refer to and cite a few of our favorite dictionaries, usage guides, and style manuals. This site is meant to be useful to students and English learners, but it is not a recognized authoritative source. You probably shouldn’t cite us in your school papers.”