According to the Kentucky Virtual Library, any information derived from an external source should be cited, including quotations, paraphrases, statistics, data or images. In addition to avoiding accusations of plagiarism, there are other reasons that citing external sources is important in academic and technical writing. Referring to the work of other accredited authors supports the information and arguments presented in written piece, enhancing its credibility. Citations also enable the reader to trace the sources that have been used to inform the writer.
In-text referencing styles involve including an abbreviated reference to a source used within the body of the document text. In contrast, endnote and footnote referencing styles provide information about sources at the bottom of the page or at the end of the text. In-text citations are sometimes referred to as parenthetical references because of the use of parentheses to contain certain bibliographic information.
According to the Purdue Online Writing Lab, the Modern Language Association (MLA) in-text citation is the referencing style most commonly used in the humanities area. In MLA style, parentheses containing the author's name and page number are placed after the relevant quote or paraphrase. Alternatively, the author's name is incorporated into the text with parenthesis containing the page number appearing at the end of the sentence. The full bibliographic details about publication are then presented in a Works Cited page at the end of the document.
The American Psychological Association (APA) style is another widely used method of in-text citation. In APA style, the author, year of publication and page number are contained in parentheses at the end of the relevant statement. Following the initial citation, when the same work is referenced, only the author and page number need to be specified unless another source by the same author from the same year has also been referenced. If the author's name is mentioned in the text, only the year and page number information are required in the citation. As with MLA style, in APA style a separate Works Cited page at the end of the document should contain full bibliographic information about the sources referenced.