Kiyoung Kim Jonghee Park Woontack Woo Marker-Less Tracking for Multi-layer Authoring in AR Books. 48-59 2009 ICEC http://dx.doi.org/10.1007/978-3-642-04052-8_5 conf/iwec/2009 db/conf/iwec/icec2009.html#KimPW09