Dictionaries belong to other documents, and the references of the paper are mainly first-class documents. Dictionaries do not belong to the main document, but are generally used as references for other documents. However, it is not absolute. For example, your thesis studies the characteristics of dictionaries of different versions or periods, and dictionaries can also be used as reference. However, if you only quote the notes of a certain entry, you should generally not refer to it. It is best to find out the source of the original document related to the content of the item to quote.