http://leiden.dachs-archive.org/archive/citrep/vancrevel2008/20080214/www.gucheng.net/ http://leiden.dachs-archive.org/archive/citrep/vancrevel2008/20080214/www.gucheng.net/ http://leiden.dachs-archive.org/archive/citrep/vancrevel2008/20080214/www.gucheng.net/