Citations
MLA, APA and Chicago have all developed guidelines on how to cite ChatGPT. The page "Associated Sources for Citations and Copyright" contains direct links to their policies and citation examples.
They differ in their approaches. For instance, both APA and Chicago are treating ChatGPT as an author, while MLA is not. Also, at this writing, Chicago recommends either putting a parenthetical note directly in the text stating that the information came from ChatGPT or, when necessary, putting it in a footnote but without any bibliographic reference. It is likely, however, that these recommendations may change over time. It might be worthwhile to discuss with students ahead of time what will be acceptable as a citation. This will bring to the forefront some of the scholarly challenges using ChatGPT presents.
Copyright
Meanwhile, many authors have stated their concerns about copyright abuses inherent to LLMs. ChatGPT is trained on information scraped from a variety of sources, some of which is likely to be copyrighted. Since ChatGPT often doesn't include a citation when its response may include primary source material, unless the user is careful to search out a correct citation for what the ChatGPT just provided, it could be viewed as plagiarism by the originator. This is also worth a discussion with students to prevent them both from inadvertently plagiarizing, but also to be more responsible users of the tool.
It is worth noting that Open AI, in its Terms and Conditions that users agree to, assigns all legal responsibility of any ChatGPT output to the user. Although untested in the courts, this would seem to remove liability from Open AI for plagiarized material and place it on the user.
Meanwhile, according to The New York Times, August 23, 2023, in one of the first cases of this type, a Federal judge recently rejected an attempt to copyright an artwork submitted by a plaintiff that was generated by AI. The U.S. Copyright Office had rejected the artist's request because it was not created by a human; the plaintiff sued. The Federal judge agreed with the Copyright Office. The plaintiff is appealing. The Copyright Office has provided guidelines to submissions that include AI contributions. Those guidelines specify that the applicants must specify which portions were created by a human, and which by AI.
Small, Zachary. "Court Rejects A.I. Role As Creator." The New York Times, 23 Aug. 2023, pp. C4.