Singles Radio Action

Back in the days when I used to subscribe to Billboard, one of my favorite sections of the magazine was Singles Radio Action, where you could find out what songs were breaking in regions of the Country. I think they did away with this in the 80's, but in the 70's it was required reading to find out what songs were to be the next big hits.
Anyway, atBillboard - Google Book Search, you can browse some of the past magazines. And the ads will be priceless.