I’ve applied for jobs a few times and this has always been a problem. Now that I’ve been out of college for a while it’s even more of a problem. I don’t have anyone from college that would even remember me. I can’t use my current coworkers because I don’t want my current employer to know I’m leaving until I have a new job lined up. I don’t keep in touch with old coworkers. I don’t do anything outside of work as far as volunteering or anything. I know I’m not supposed to use friends or family. Who is even left after that? The only people I have the contact info for are friends, family, and my current boss.
As a former college lecturer I definitely remember my students for years, so thats still an option. I’d do whatever lecturer you knew best and then the admin department who can confirm that you were there.