Soonmok Kwon Jeonggyu Kim Cheeha Kim An Efficient Tree Structure for Delay Sensitive Data Gathering in Wireless Sensor Networks. 738-743 2008 AINA Workshops http://doi.ieeecomputersociety.org/10.1109/WAINA.2008.268 conf/aina/2008w db/conf/aina/ainaw2008.html#KwonKK08