Werner Breitfuss Helmut Prendinger Mitsuru Ishizuka Automatic Generation of Non-verbal Behavior for Agents in Virtual Worlds: A System for Supporting Multimodal Conversations of Bots and Avatars. 153-161 2009 HCI (12) http://dx.doi.org/10.1007/978-3-642-02774-1_17 conf/hci/2009-12 db/conf/hci/hci2009-12.html#BreitfussPI09