Petr Aksenov Geert Vanderhulst Kris Luyten Karin Coninx Ambient Compass: One Approach to Model Spatial Relations. 183-191 2009 HCI (11) http://dx.doi.org/10.1007/978-3-642-02809-0_20 conf/hci/2009-11 db/conf/hci/hci2009-11.html#AksenovVLC09