A professional references page is a short, separate document listing people who can vouch for your work when an employer asks. It is not part of your resume and it is not a cover letter. It exists for one specific moment late in a hiring process: the point where a company has decided you are a serious candidate and wants to confirm what you told them by talking to people who worked with you.
Because that moment comes after most of the impression-making is done, the page itself does not need to sell you. It needs to be accurate, easy to act on, and formatted the way a hiring coordinator expects, so nothing about it slows the process down or raises a question it did not need to raise.