PSP: How to Upgrade from 3.60 m33 to 3.71 m33-2 Custom Firmware - YouTube
PSVita News: TheFlow releases h-encore² with support for FW 3.71 - You can now hack the latest PSVita firmware again and run your favourite homebrew on every Vita/PSTV! - Wololo.net
Psp 3.71 M33-2 Update to 6.61 latest software - YouTube