PSP: Returning to Firmware 6.60 from Firmware 6.61 - YouTube
New to me GO! : PSP
Updating The PSP System Software to 6.60 / 6.61 - pspunk
Sony Updates Its PSP Console with Firmware 6.61 – Download Links Available
PSP Custom Firmware 6.00-6.61
Infinity 2.0 released for the PSP, allows for persistent CFW on all models of PSPs on 6.60 and 6.61 | Page 2 | GBAtemp.net - The Independent Video Game Community
PSP Custom Firmware 6.00-6.61
PSP: Homebrew / Custom Firmware / New Owner Catch-all | Gamers With Jobs
Custom Firmware Help : r/PSP
Updating The PSP System Software to 6.60 / 6.61 - pspunk
Sony Updates Its PSP Console with Firmware 6.61 – Download Links Available
4 Ways to Upgrade Your PSP Firmware - wikiHow
Mandatory PSP Firmware 6.61 Released Today, First in Three Years - Hardcore Gamer
PSP: Updating from the 3.xx OE CFWs to the 6.60 ME CFW - YouTube
4 Ways to Upgrade Your PSP Firmware - wikiHow
How To Install PSP 6.60 PRO-C2 Custom Firmware! - YouTube