The term 'MENTION AS A SOURCE' can be summarized by the word 'CITE', which is a four-letter word. CITE is a verb meaning to quote or refer to (a book, author, etc.) as an authority for or evidence of a statement. It is often used in academic writing to give credit to the original author of a work. Citing sources is important to avoid plagiarism and to ensure that the reader can access the original source material.