7 String Chords in Drop A Tuning » Strings Of Rage™
6 String Guitar Chords Poster Learning Practice Reference Chart Parts | eBay
Guitar Barre Chords on the 5th and 6th Strings - Acoustic Music TV
3-String Open Chords (Major) - Chris Tripolino
Here's the Chord Quality Cycle Exercise off the 4th string (per request). If people find these useful I might post another with the full exercise in one image showing the chords off