Risen from the dead: PSP Firmware 6.61 is now available! - Wololo.net
PSP: 6.61 Infinity - Davee's 'Permanent Patch' for System Software 6.61 - Wololo.net
Sony PSP 2003 black CFW 6.61 | MyRetroShop.com
How to Mod Any PSP on Firmware 6.61 or Lower! - Infinity 2.0 Permanent CFW
PSP: Custom Firmwares for Firmware 6.61 possible - Currently being updated! - Wololo.net
How to Download PSP Games and Transfer them to Your PSP
Infinity 2.0 released for the PSP, allows for persistent CFW on all models of PSPs on 6.60 and 6.61 | GBAtemp.net - The Independent Video Game Community
Modifica PSP - CFW 6.61 Pro-C F3 | TecnoW
PlayStation Guide
PSP-1006 Sony PlayStation Portable Console 6.61 Pro-C∞ Infinity 1GB + 2 Games | eBay
Why do so many people prefer 6.60>6.61? : r/PSP
Sony PSP 1000 Custom Firmware Installation Service
just sharing 6.61 PRO-C cIPL flashed PSP-1000 and PSP-2000 and 6.61 PRO-C Infinity PSP-3000 : r/PSP