On April 18, 2000, Britney Spears appeared on VIVA Interaktiv, a German TV Show. She performed Oops!... I Did It Again.
There's also the interview of the show:
Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
On April 18, 2002, she performed a showcase at Pepsi Chart Australia that included I'm a Slave 4 U, Boys and I'm Not a Girl, Not Yet a Woman.
Thanks to Britney-Online for the HQ videos of the performances @CJMCH
Related: