Urgent Need help: Public

Can anyone give me a link to the Official INS documentation about the legal status a Vientmese who came to US >10 years ago as a Public Interest Parole?

I know the Vietmese with PIP are treated the same as a permanent resident in terms of work permission and school (e.g. tuition). However, I don't find any official documents about this to convince a small school in order to register for classes. They haven't seen any case like mine.

All I have is the I-94 that indicates I am a Vietmese and enter US under Public Interest Parole.

Thanks a lot.