How do I give users rights to edit one page only?

I have done EXTENSIVE research on this and have turned up no sensible solution. There must be one, and I appreciate any help you can give me.

I’d like to have a WordPress site which has several pages about shopping centers. Each center will have its own page. I’d like each owner of each center to have the ability to edit their own page and nothing else. What would be the best way to give (roughly) 30 users access to each of their individual pages? Anyone can see the pages, but editing rights is restricted.

Thank you very much.
Multimediocrity