I'm using Pimsleur audiobooks via Audible.com to help learn Mandarin.
There seem to be 2 different series, "Pimsleur Digital Mandarin Chinese" and "Pimsleur Mandarin Chinese" but I can't find any explanation of the distinction.
Does anyone know what the difference is, so that I'll know which ones I want to keep buying?
Here is a screenshot of the different series:
