Minghui Jiang Brendan Mumey Zhongping Qin Andrew Tomascak Binhai Zhu Approximations for Two Decomposition-Based Geometric Optimization Problems. 90-98 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3045&spage=90 2004 conf/iccsa/2004-3 ICCSA (3) db/conf/iccsa/iccsa2004-3.html#JiangMQTZ04