Findings:
- dy/dx
- d/dx
- the dx Convention
- dx
- Oberheim DX
- Oberheim MIDI DX
- DX Codes
- Tetris DX
- dx (user)
- The Legend of Zelda: Link's Awakening DX
- Sonic Adventure DX
If you Log in you could create a "DX 7" node. If you don't already have an account, you can register here.