Each discipline has its own citation style. For literature, the citation style is The Modern Language Association (MLA) Style. The MLA is a scholarly organization devoted to the study and teaching of language and literature. The MLA produces guidelines for the proper formatting and documentation of research papers in English and some disciplines in the humanities. Their guidelines are published in the MLA Handbook for Writers of Research Papers and the MLA Style Manual and Guide to Scholarly Publishing.
It is important to cite sources used in your research paper for the following reasons:
The video below, from North Carolina State University(NCSU), explains what a citation is, and why we cite.