graduate admissions - How can I obtain an academic reference, if I have been out of college for a very long time?

I have completed my Master's degree 25+ years ago, and I decided to go back to college to further my education with a Doctorate degree. I fulfill all the requirements, except for the need to provide 2 academic references.

How should I proceed to obtain the references? Should I hunt down my former professors in their retirement and hope they retain their faint memories of me?