Human Head Tracking Using Adaptive Appearance Models with a Fixed-Viewpoint Pan-Tilt-Zoom Camera. - Kiyotake Yachi; Toshikazu Wada; Takashi Matsuyama (FG, 2000)

Tracking Human Heads Based on Interaction between Hypotheses with Certainty. - Akihiro Sugimoto; Kiyotake Yachi; Takashi Matsuyama (SCIA, 2003)