When writing a research paper or presenting any information that is not your own, original work, you are expected to acknowledge the sources you consulted in forming and supporting your ideas. Failing to do so may cause you to be guilty of plagiarism: claiming or using another person's work as your own (intentionally or unintentionally) without crediting the original author(s).
Proper citation requires the inclusion of a brief in-text notation as well as a detailed identification of the source you consulted. The form that these citations will take, is usually dictated by the profession or subject area to which the research pertains. The three most common styles, and the subjects that use them, are the following:
APA Style (7th ed.): Established by the American Psychological Association, this style is most often used in the fields of Social Science (including Psychology, Education, Economics, etc.), Business, Nursing, and some Sciences.
MLA Style (9th ed.): This style, established by the Modern Language Association, is used by students and scholars in English Language & Literature, Comparative Literature, Cultural Studies, Foreign Languages, and other areas in the humanities.
Chicago Style (17th ed.): was created by the University of Chicago and is used most often in the fields of History and Religion.
While you are a student, however, you should ALWAYS use the style required by your assignment or your teacher.
There are a number of free, online tools which can help you create a citation using your preferred (or specified) style. A couple of FREE options to consider are linked below: