See, walk, and kick: Humanoid robots start to play soccer. - Sven Behnke; Michael Schreiber; Jörg Stückler; Reimund Renner; Hauke Strasdat (Humanoids, 2006)

Instability Detection and Fall Avoidance for a Humanoid using Attitude Sensors and Reflexes. - Reimund Renner; Sven Behnke (IROS, 2006)