Michael Kleis Eng Keong Lua Xiaoming Zhou Hierarchical Peer-to-Peer Networks Using Lightweight SuperPeer Topologies. 143-148 2005 conf/iscc/2005 ISCC http://doi.ieeecomputersociety.org/10.1109/ISCC.2005.78 db/conf/iscc/iscc2005.html#KleisLZ05