In all types of scholarly and research writing it is necessary to document the source works that underpin particular concepts, positions, propositions and arguments with citations. These citations serve a number of purposes:

Help readers identify and relocate the source work.
Readers often want to relocate a work you have cited, either to verify the information, or to learn more about issues and topics addressed by the work. It is important that readers should be able to relocate your source works easily and efficiently from the information included in your citations (see the “Citation Structure” topic on the following page for details), in the sources available to them - which may or may not be the same as the sources available to you .
Provide evidence that the position is well-researched.
Scholarly writing is grounded in prior research. Citations allow you to demonstrate that your position or argument is thoroughly researched and that you have referenced, or addressed, the critical authorities relevant to the issues.
Give credit to the author of an original concept or theory presented.
Giving proper attribution to those whose thoughts, words, and ideas you use is an important concept in scholarly writing. For these reasons, it is important to adopt habits of collecting the bibliographic information on source works necessary for correct citations in an organized and thorough manner.