Wikipedia on DMR Radio: [Wikipedia on DMR]
[PDF: Excellent Cheat-Sheet on DMR by Tim Helming WT1IM ]
[HTML: Excellent Cheat-Sheet on DMR by Tim Helming WT1IM ]
[PDF: DMR CodePlug 101 by David Hull KC6N - Specifically for the Anytone 868 & 878 but generally informative for all DMR]
[DMR Simplex Frequencies]