A bibliography is a list of sources that were used or consulted to write a research paper, book, or article. It is a specialized aspect of library science and documentation science. A bibliography can include references cited in the body of the paper and sources from general research. There are two types of bibliographies: enumerative bibliography and descriptive bibliography. An enumerative bibliography is a list of books for further study or of works consulted by an author, while a descriptive bibliography is the study of books as physical objects and the systematic description of books as objects. A bibliography should include all the works from which you have borrowed material. An annotated bibliography is the same as a bibliography, with one important difference: in an annotated bibliography, the bibliographic information is followed by a brief description of the content, quality, and usefulness of the source. A works cited page is a list of all the works from which you have borrowed material. Bibliographic information can be found at the end of a book, article, or research paper.