These databases provide citations for scholarly articles, book chapters, conference proceedings, dissertations, and other literature.
Google Scholar provides a simple way to broadly search for scholarly literature. From one place, you can search across many disciplines and sources: peer-reviewed papers, theses, books, abstracts and articles, from academic publishers, professional societies, preprint repositories, universities and other scholarly organizations. It is also very useful for seeing if other scholars have cited a book, article, etc. Search on the title, and then follow the "Cited by ..." link.
Articles, essays, book chapters, conference proceedings, etc., can be found in databases subscribed to by Columbia University Libraries (CUL). Barnard affiliates can access all the CUL resources, which includes over 1600 databases.