Yukio Kagawa Discrete Huygens' Modelling and Simulation for Wave Propagation. 1-11 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3398&spage=1 2004 conf/asiasim/2004 AsiaSim db/conf/asiasim/asiasim2004.html#Kagawa04