WorldCatwww.worldcat.org/ provides information about the holdings of many thousands of libraries worldwide. And once you figure out where something is, most libraries will let you use it in house.
Google Scholarscholar.google.com lets you search for scholarly literature across articles, theses, books, abstracts and court opinions, from academic publishers, professional societies, online repositories, universities and other web sites. Some of what you find will be freely available. Some sites will offer you the opportunity to purchase an article. You can also request articles on interlibrary loan from your local library.