Getting references after a company closes - any advice?

My manager was laid off too and I am unsure who to use as a reference. HR only confirms titles and dates. How do you ask politely?

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.

Thanks for writing this out. I went through something close to it 6 months ago, and it got easier once I kept a simple log of every call and form.