I am moving out and I came across these advertising books from the ringling bros. circus that are signed from people who participated in the show. They are from 20th-25th celebrations and I was just wondering if they would be worth anything. I thought they may be worth something since they are signed by acrobats, clowns, and other such people. Could they be worth anything and if so how much?

Moved to collectibes so they can get better answers