Where can I find the information from the back of a TAC if I don't have a physical copy?
If you are using Fore Flight you can Turn On Legends which will show you the legend information for the map. You may also be able to download the information somewhere else in the application. It will help if you inform us of which app you are using. 

In the documents section of Fore Flight there are some other Atlanta area documents. Im not sure what the back of the cart looks like so I'm not sure if any of them are correct but there is the Atlanta FLY chart and the Atlanta Class B diagram.